Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-04T19:51:31.961Z Has data issue: false hasContentIssue false

The Victoria University of Manchester’s contributions to the development of aeronautics

Published online by Cambridge University Press:  03 February 2016

J. A. D. Ackroyd*
Affiliation:
Former Aerospace Division, Manchester School of Engineering, The Victoria University of Manchester, Manchester, UK

Extract

This issue of the Aeronautical Journal celebrates the 50th anniversary of the foundation of the Honours Degree Course in Aeronautical Engineering at the Victoria University of Manchester. The following article therefore describes the aeronautical research and teaching activities of that university up to its recent amalgamation with the University of Manchester Institute of Science and Technology (UMIST) to form the present-day University of Manchester. This juncture provides a further justification for recording the Victoria University’s achievements.

Both the Victoria University and UMIST had their roots in the nineteenth century although, apart from the relatively brief period of the First World War, neither of them was particularly involved in aeronautics until after the Second World War. However, as Sections 6.0-10.0 seek to demonstrate, thereafter the Victoria University’s involvement became considerable. The preceding Sections describe the origins of the Victoria University and UMIST and, in the case of the former institution, the subsequent activities of its staff and graduates in engineering and mathematics which, although not always specifically aeronautical in content, nonetheless had a profound influence on the development of the aeronautical sciences.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2007 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Jackson, J.D. Osborne Reynolds: scientist, engineer and pioneer, Proc Roy Soc A, 1995, 451, pp 4986.Google Scholar
2. Reynolds, O. An experimental investigation of the circumstances which determine whether the motion of water shall be direct or sinuous and of the law of resistance in parallel channels, Phil Trans Roy Soc A, 1883, 174, pp 933982.Google Scholar
3. Van Dyke, M.D. An Album of Fluid Motion, 1982, Parabolic Press, Stanford, CA.Google Scholar
4. Thomson, W. On the vortex theory of the luminiferous aether. (On the propagation of laminar motion through a turbulently moving inviscid liquid), British Assoc Rep, 1887, pp 486495.Google Scholar
5. Sommerfeld, A.J.W. Ein Beitrag zur hydrodynamischen Erklärung der turbulenten Flüssigkeitsbewegungen, 1909, Reale Accademia Lincei, Atti del IV Congresso Internazionale dei Matematici, Roma 1908, 3, pp 116124.Google Scholar
6. Stokes, G.G. On the effect of the internal friction of fluids on the motion of pendulums, Trans Camb Phil Soc, 1851, 9, pp 8106.Google Scholar
7. Von Helmholtz, H.L.F. Über ein Theorem, geometrisch ähnliche Bewegungen flüssiger Körper betreffend, nebst Anwendung auf das Problem, Luftballons zu lenken, Monatsberichte der königl Akademie der Wissenschaften zu Berlin, 1873, pp 501514: Wissenschaftliche Abhandlungen, 1873, 1, pp 158171.Google Scholar
8. Rayleigh, Lord. Note as to the application of the principle of dynamic similarity, 1910, ACA, R & M No 15 (Part 2).Google Scholar
9. Reynolds, O. On the extent and action of the heating surface for steam boilers, Proc Man Lit Phil Soc, 1875, 14, pp 712.Google Scholar
10. Reynolds, O. On the dynamical theory of incompressible viscous fluids and the determination of the criterion, Phil Trans Roy Soc A, 1896, 186, pp 123164.Google Scholar
11. Reynolds, O. On the flow of gases, Proc Man Lit Phil Soc, 1887, 10, pp 164182.Google Scholar
12. Lamb, H. Hydrodynamics (Sixth Edition), Cambridge University Press, 1932.Google Scholar
13. Kutta, M.W. Auftriebskräfte in strömenden Flüssigkeiten, Illus Aeronautische Mitteilungen, 1902, 6, pp 133135.Google Scholar
14. Zhukovskil, N.E. On annexed vortices (in Russian), Trans Physical Section of the Imperial Society of the Friends of Natural Science, Moscow, 1906, 13, pp 1225.Google Scholar
15. Prandtl, L. Über Flüssigkeitsbewegung bei sehr kleiner Reibung, Verhandlungen des dritten internationalen Mathematiker-Kongresses, 1904, Heidelberg, pp 489491, Teubner, Leipzig, 1904.Google Scholar
16. Mcguinness, B. Wittgenstein: A Life, 1988, Duckworth, London.Google Scholar
17. Penrose, H. Architect of Wings, Airlife, 1985, Shrewsbury.Google Scholar
18. Stanton, T.E. Report on the experimental equipment of the Aeronautical Department of the National Physical Laboratory, 1910, ACA, R & M No 25.Google Scholar
19. Stanton, T.E., Pannell, J.R. and Marshall, D. Heat transmission over surfaces, 1917, ACA, R & M No 243.Google Scholar
20. Stanton, T.E. The development of a high speed wind channel for research in external ballistics, Proc Roy Soc A, 1931, 131, pp 122132.Google Scholar
21. Ackroyd, J.A.D. The United Kingdom’s contributions to the development of aeronautics; Part 4. The origins of the jet age, Aeronaut J, January 2003, 107, (1067), pp 147.Google Scholar
22. Gibson, A.H. and Chorlton, A.E.L. (Eds.) Internal-Combustion Engineering (Third Edition), 1938, Gresham Publishing Co, London.Google Scholar
23. Ackroyd, J.A.D. The United Kingdom’s contributions to the development of aeronautics; Part 3. The development of the streamlined monoplane (the 1920s-1940s), Aeronaut J, May 2002, 106, (1059), pp 217268.Google Scholar
24. ANON Investigations carried out at the Royal Aircraft Establishment on the use of blowers for super-charging aero engines, 1919, ACA (Internal Combustion Engine Sub-Committee), ICE 230.Google Scholar
25. Lighthill, M.J. The inaugural Goldstein Lecture – Some challenging new applications for basic mathematical methods in the mechanics of fluids that were originally pursued with aeronautical aims, Aeronaut J, 1990, 94, pp 4152.Google Scholar
26. Ackroyd, J.A.D. Sydney Goldstein, FRS, Hon FRAeS – An appreciation, Aerospace, 1989, 16, (6), pp 2630.Google Scholar
27. Lighthill, M.J. Sydney Goldstein, Biographical Memoirs of Fellows of the Royal Society, 1990, 36, pp 175197.Google Scholar
28. Goldstein, S. On the vortex theory of screw propellers, Proc Roy Soc A, 1929, 123, pp 440465.Google Scholar
29. Goldstein, S. (Ed), Modern Developments in Fluid Dynamics, Vols I, II, 1938, Oxford University Press.Google Scholar
30. Goldstein, S. Low drag and suction aerofoils, JAS, 1948, 15, pp 189220.Google Scholar
31. Goldstein, S. On laminar boundary layer flow near a position of separation, QJMAM, 1948, 1, pp 4369.Google Scholar
32. Goldstein, S. On the law of decay of homogeneous isotropic turbulence and the theories of the equilibrium and similarity spectra, Proc Camb Phil Soc, 1950, 47, pp 554574.Google Scholar
33. Goldstein, S. and Ward, G.N. The linearized theory of conical fields in supersonic flow, with applications to plane aerofoils, Aeronaut Q, 1950, 2, pp 3984.Google Scholar
34. Lighthill, M.J. Supersonic flow past bodies of revolution, 1945, ARC, R & M No 2003.Google Scholar
35. Lighthill, M.J. Supersonic flow past slender pointed bodies of revolution at yaw, QJMAM, 1948, 1, pp 7689.Google Scholar
36. Lighthill, M.J. Supersonic flow past bodies of revolution, the slope of whose meridian section is discontinuous, QJMAM, 1948, 1, pp 90102.Google Scholar
37. Lighthill, M.J. The hodograph transformation in trans-sonic flow. Parts I-IV, Proc Roy Soc A, 1947, 191, pp 323369; 192, pp 135142.Google Scholar
38. Lighthill, M.J. Contributions to the theory of heat transfer through a laminar boundary layer, Proc Roy Soc A, 1950, 202, pp 359377.Google Scholar
39. Lighthill, M.J. The shock strength in supersonic ‘conical fields’, Phil Mag Series 7, 1949, 40, pp 12011223.Google Scholar
40. Lighthill, M.J. A technique for rendering approximate solutions to physical problems uniformly valid, Phil Mag Series 7, 1949, 40, pp 11791201.Google Scholar
41. Pedley, T.J. James Lighthill and his contributions to fluid mechanics, Annu Rev Fluid Mech, 2001, 33, pp 141.Google Scholar
42. Lighthill, M.J. Dynamics of a dissociating gas. Part 1. Equilibrium flow, JFM, 1956, 2, pp 132.Google Scholar
43. Lighthill, M.J. Dynamics of a dissociating gas. Part 2. Quasi-equilibrium transfer theory, JFM, 1960, 8, pp 161182.Google Scholar
44. Lighthill, M.J. Viscosity effects in sound waves of finite amplitude, 1956, Surveys in Mechanics (Batchelor, G.K. and Davies, R.M (Eds)), pp 250351, Cambridge University Press.Google Scholar
45. Howarth, L. (Ed), Modern Developments in Fluid Dynamics, High Speed Flow, Vols I & II, 1953, Oxford University Press.Google Scholar
46. Lighthill, M.J. Higher Approximations, 1954, General Theory of High Speed Aerodynamics; Vol VI, High Speed Aerodynamics and Jet Propulsion (Sears, W.R. (Ed)), pp 345489, Princeton University Press.Google Scholar
47. Rosenhead, L. (Ed)), Laminar Boundary Layers, 1963, Oxford University Press.Google Scholar
48. Lighthill, M.J. On sound generated aerodynamically. Parts I & II, Proc Roy Soc A, 1952, 211, pp 564587; 1954, 222, pp 132.Google Scholar
49. Lighthill, M.J. Sound generated aerodynamically (The Bakerian Lecture), Proc Roy Soc A, 1962, 267, pp 147181.Google Scholar
50. Chester, W. Supersonic flow past wing-body combinations, Aeronaut Q, 1953, 4, pp 287314.Google Scholar
51. Curle, S.N. The influence of solid boundaries upon aerodynamic sound, Proc Roy Soc A, 1955, 231, pp 505514.Google Scholar
52. Goldsworthy, F.A. Supersonic flow over thin symmetrical wings with given surface pressure distribution, Aeronaut Q, 1952, 3, pp 263279.Google Scholar
53. Stocker, P.M. Supersonic flow past bodies of revolution with thin wings of small aspect ratio, Aeronaut Q, 1951, 3, pp 6179.Google Scholar
54. Whitham, G.B. The behaviour of supersonic flow past a body of revolution, far from the axis, Proc Roy Soc A, 1950, 201, pp 89109.Google Scholar
55. Freeman, N.C. On the theory of hypersonic flow past plane and axially symmetric bluff bodies, JFM, 1956, 1, pp 366387.Google Scholar
56. Freeman, N.C. Non-equilibrium flow of an ideal dissociating gas, JFM, 1958, 4, pp 407425.Google Scholar
57. Chisnell, R.F. The motion of a shock wave in a channel, with applications to cylindrical and spherical shock waves, JFM, 1957, 2, pp 286298.Google Scholar
58. Riley, N. Effects of compressibility on a laminar wall-jet, JFM, 1958, 4, pp 615628.Google Scholar
59. Riley, N. Interaction of a shock wave with a mixing region, JFM, 1960, 7, pp 321339.Google Scholar
60. Hancock, G.J. The self-propulsion of microscopic organisms through liquids, Proc Roy Soc A, 1953, 217, pp 96121.Google Scholar
61. Lighthill, M.J. A new method of two-dimensional aerodynamic design, 1945, ARC, R & M No 2112.Google Scholar
62. Glauert, M.B. The application of the exact method of aerofoil design, 1947, ARC, R & M No 2683.Google Scholar
63. Glauert, M.B. and Lighthill, M.J. The axisymmetric boundary layer on a long thin cylinder, Proc Roy Soc A, 1955, 230, pp 188203.Google Scholar
64. Glauert, M.B. The wall-jet, JFM, 1956, 1, pp 625643.Google Scholar
65. Ursell, F.J. and Ward, G.N. On some general theorems in the linearized theory of compressible flow, QJMAM, 1950, 3, pp 326348.Google Scholar
66. Ward, G.N. Supersonic flow past slender pointed bodies, QJMAM, 1949, 2, pp 7597.Google Scholar
67. Ward, G.N. Linearized Theory of Steady High-Speed Flow, 1955, Cambridge University Press.Google Scholar
68. Lord, W.T. A British approach to the area rule, Flight, 1955, 52, pp 769771.Google Scholar
69. Eminton, E. and Lord, W.T. Note on the numerical evaluation of the wave drag of smooth slender bodies using optimum area distributions for minimum wave drag, JRAeS, 1956, 60, pp 6163.Google Scholar
70. Oswatitsch, K. The area rule, Applied Mechanics Review, 1957, 10, pp 543545.Google Scholar
71. Illingworth, C.R. Steady flow in the laminar boundary layer of a gas, Proc Roy Soc A, 1949, 199, pp 533558.Google Scholar
72. Stewartson, K. Correlated compressible and incompressible boundary layers, Proc Roy Soc A, 1949, 200, pp 8499.Google Scholar
73. Watson, E.J. The asymptotic theory of boundary-layer flow with suction, 1947, ARC, R & M No 2619.Google Scholar
74. Watson, E.J. The spread of a liquid jet over a horizontal plate, JFM, 1964, 20, pp 481499.Google Scholar
75. Watson, E.J. Boundary-layer growth, Proc Roy Soc A, 1955, 231, pp 104116.Google Scholar
76. Terrill, R. M. Laminar boundary-layer flow near separation with and without suction, Phil Trans Roy Soc A, 1960, 253, pp 55100.Google Scholar
77. Stewartson, K. On Goldstein’s theory of laminar separation, Quart J Mech, 1958, 11, pp 399410.Google Scholar
78. Watson, E.J. The equation of similar profiles in boundary-layer theory with strong blowing, Proc Roy Soc A, 1966, 294, pp 208234.Google Scholar
79. Mair, W.A. (Ed). Research on high speed aerodynamics at the Royal Aircraft Establishment from 1942 to 1945, 1950, ARC, R & M No 2222.Google Scholar
80. Mair, W.A. The sensitivity and range required in a Toepler schlieren apparatus for photography of high-speed air flow, Aeronaut Q, 1952, 4, pp 1950.Google Scholar
81. Collis, D.C. The dust problem in hot-wire anemometry, Aeronaut Q, 1952, 4, pp 93102.Google Scholar
82. Wyatt, L.A. A technique for cleaning hot-wires used in anemometry, J Sci Instr, 1953, 30, pp 1314.Google Scholar
83. Bardsley, O. and Mair, W.A. The interaction between an oblique shock wave and a turbulent boundary layer, Phil Mag Series 7, 1951, 42, pp 2936.Google Scholar
84. Mair, W.A. Experiments on separation of boundary layers on probes in front of blunt-nosed bodies in a supersonic air stream, Phil Mag Series 7, 1952, 43, pp 695716.Google Scholar
85. Johannesen, N.H. Experiments on two-dimensional supersonic flow in corners and over concave surfaces, Phil Mag Series 7, 1952, 43, pp 567580.Google Scholar
86. Bardsley, O. The conditions at a sharp leading edge in supersonic flow, Phil Mag Series 7, 1951, 42, pp 255262.Google Scholar
87. Bardsley, O. and Mair, W.A. Separation of the boundary layer at a slightly blunt leading edge in supersonic flow, Phil Mag Series 7, 1952, 43, pp 344352.Google Scholar
88. Johannesen, N.H. and Mair, W.A. Experiments with large pitot tubes in a narrow supersonic wake, JAS, 1952, 19, (11), pp 785786.Google Scholar
89. Johannesen, N.H. Experiments on supersonic flow past bodies of revolution with annular gaps of rectangular section, Phil Mag Series 7, 1955, 46, pp 3139.Google Scholar
90. Hall, I.M. Experiments on supersonic flow over flat-nosed circular cylinders at yaw, Phil Mag Series 7, 1954, 45, pp 333343.Google Scholar
91. Hall, I.M. Experiments on supersonic flow over flat-nosed circular cylinders at yaw – II: Pressure measurements on a cylinder at 10º yaw, Phil Mag Series 7, 1955, 46, pp 5360.Google Scholar
92. Donaldson, I.S. The effect of sting supports on the base pressure of a blunt-based body in a supersonic stream, Aeronaut Q, 1955, 6, pp 221229.Google Scholar
93. Gerrard, J.H. Measurement of sound from circular cylinders in an airstream, Proc Phys Soc B, 1955, 68, pp 453461.Google Scholar
94. Gerrard, J.H. An investigation of the noise produced by a subsonic air jet, JAS, 1956, 23, (9), pp 855867.Google Scholar
95. Nahum, A. The Royal Aircraft Establishment from 1945 to Concorde, 1999, Cold War, Hot Science: Applied Research in Britain’s Defence Laboratories 1945-1990, pp 2958, (Bud, R. and Gummett, P. (Eds)), Harwood Academic Publishers, Amsterdam.Google Scholar
96. Owen, P.R. and Klanfer, L. On the laminar boundary layer separation from the leading edge of a thin aerofoil, 1953, ARC, CP No 220.Google Scholar
97. Owen, P.R. and Thomson, W.R. Heat transfer across rough surfaces, JFM, 1963, 15, pp 321334.Google Scholar
98. Owen, P.R. Dust deposition from a turbulent airstream, 1960, Aerodynamic Capture of Particles, (Richardson, E.G. (Ed)), pp 825, Pergamon Press, Oxford.Google Scholar
99. Bakke, P. An experimental investigation of a wall jet, JFM, 1957, 2, pp 467472.Google Scholar
100. Johannesen, N.H. The mixing of free axially-symmetrical jets of Mach number 1⋅40, 1957, ARC, R & M No 3291.Google Scholar
101. Johannesen, N.H. Further results on the mixing of free axially-symmetric jets of Mach number 1·40, 1959, ARC, R & M No 3292.Google Scholar
102. Sharp, A.W. The supersonic flow past a leading edge separation bubble, JFM, 1959, 5, pp 445459.Google Scholar
103. Owen, P.R. and Zienkiewicz, H.K. The production of uniform shear flow in a wind tunnel, JFM, 1957, 2, pp 521531.Google Scholar
104. Hall, I.M. The displacement effect of a sphere in a two-dimensional shear flow, JFM, 1956, 1, pp 142162.Google Scholar
105. Zienkiewicz, H.K. Flow about cones at very high speeds, Aeronaut Q, 1957, 8, pp 384394.Google Scholar
106. Gerrard, J. H. Piezoelectric pressure gauges for use in a shock tube, Acustica, 1959, 9, pp 1723.Google Scholar
107. Young, A.D. and Lighthill, M.J. Paul Robert Owen, 1992, Biographical Memoirs of Fellows of the Royal Society, 38, pp 267285.Google Scholar
108. Ellison, T.H. and Turner, J.S. Turbulent entrainment in stratified flows, JFM, 1959, 6, pp 423448.Google Scholar
109. Ellison, T.H. A note on the velocity profile and longitudinal mixing in a broad open channel, JFM, 1960, 8, pp 3340.Google Scholar
110. Turner, J.S. Intermittent release of smoke from chimneys, J Mech Eng Sci, 1960, 2, pp 97100.Google Scholar
111. Turner, J.S. A comparison between buoyant vortex rings and vortex pairs, JFM, 1960, 7, pp 419432.Google Scholar
112. Ellison, T.H. and Turner, J.S. Mixing of dense fluid in a turbulent pipe flow. Part 1. Overall description of the flow; Part 2. Dependence of transfer coefficients on local stability, JFM, 1960, 8, pp 514528; 8, pp 529544.Google Scholar
113. Hall, I.M. and Rogers, E.W.E. The flow pattern on a tapered swept-back wing at Mach numbers between 0·6 and 1·6, 1960, ARC, R & M No 3271.Google Scholar
114. Rogers, E.W.E. and Hall, I.M. An introduction to the flow about plane swept-back wings at transonic speeds, JRAeS, 1960, 64, pp 449464.Google Scholar
115. Hall, I.M. Transonic flow in two-dimensional and axially-symmetric nozzles, QJMAM, 1962, 15, pp 487508.Google Scholar
116. Hall, I.M. and Sutton, E.P. Transonic flow in ducts and nozzles, 1964, Symposium Transsonicum (Oswatitsch, K. (Ed)), pp 325344, Springer-Verlag, Berlin.Google Scholar
117. Moore, A.W. The transonic flow in the throat region of a two-dimensional nozzle with walls of arbitrary smooth profile, 1967, ARC, R & M No 3481.Google Scholar
118. Moore, A.W. and Hall, I.M. Transonic flow in the throat region of an annular nozzle with an arbitrary smooth profile, 1967, ARC, R & M No 3480.Google Scholar
119. Mccabe, A. Design of a supersonic nozzle, 1967, ARC, R & M No 3440.Google Scholar
120. Mccabe, A. The three-dimensional interaction of a shock wave with a turbulent boundary layer, Aeronaut Q, 1966, 17, pp 231252.Google Scholar
121. Stow, P. The interaction of a sonic jet with a surrounding subsonic stream, Aeronaut Q, 1974, 25, pp 232244.Google Scholar
122. Gerrard, J.H. An experimental investigation of the oscillating lift and drag of a circular cylinder shedding turbulent vortices, JFM, 1961, 11, pp 244256.Google Scholar
123. Gerrard, J.H. The calculation of the fluctuating lift on a circular cylinder and its application to the determination of aeolian tone intensity, 1963, AGARD Rep No 463.Google Scholar
124. Gerrard, J.H. Numerical computation of the magnitude and frequency of the lift on a circular cylinder, Phil Trans Roy Soc A, 1967, 261, pp 137162.Google Scholar
125. Bloor, M.S. and Gerrard, J.H. Measurements on turbulent vortices in a cylinder wake, Proc Roy Soc A, 1966, 294, pp 319342.Google Scholar
126. Gerrard, J.H. The wakes of cylindrical bluff bodies at low Reynolds number, Phil Trans Roy Soc A, 1978, 288, pp 351382.Google Scholar
127. Anagnostopoulos, E. and Gerrard, J.H. A towing tank with minimal background motion, J Phys E: Sci Instrum, 1976, 9, pp 951954.Google Scholar
128. Gerrard, J.H. Flow visualisation by dye and optical interferometer, 1987, Fourth International Symposium on Flow Visualisation (Véret, C. (Ed)), pp 773777, Springer-Verlag, Berlin.Google Scholar
129. Green, R.B. and Gerrard, J.H. An optical interferometric study of the wake of a bluff body, JFM, 1991, 226, pp 219242.Google Scholar
130. Honji, H. The starting flow down a step, JFM, 1975, 69, pp 229240.Google Scholar
131. Gerrard, J.H. An experimental investigation of pulsating turbulent water flow in a tube, JFM, 1971, 46, pp 4364.Google Scholar
132. Gerrard, J.H. and Hughes, M.D. The flow due to an oscillating piston in a cylindrical tube: a comparison between experiment and simple entrance flow theory, JFM, 1971, 50, pp 97106.Google Scholar
133. Gerrard, J.H. and Taylor, L.A. Mathematical model representing blood flow in arteries, Med Biol Eng Comput, 1977, 15, pp 611617.Google Scholar
134. Savvides, C. N. and Gerrard, J.H. Numerical analysis of the flow through a corrugated tube with application to arterial prostheses, JFM, 1984, 138, pp 129160.Google Scholar
135. Gerrard, J.H. An experimental test of the theory of waves in fluid-filled deformable tubes, JFM, 1985, 156, pp 321347.Google Scholar
136. Charlesworth, D. and Gerrard, J.H. Atherosclerosis and disturbances in flow, 1988, Annals of Vascular Surgery, 2, pp 5762.Google Scholar
137. Johnson, A.W. and Gerrard, J.H. Calculation of steady and oscillating flows in tubes using a vorticity transport algorithm, Int J Num Meth Fluids, 1996, 23, pp 12411262.Google Scholar
138. Johannesen, N.H. Analysis of vibrational relaxation regions by means of the Rayleigh-line method, JFM, 1961, 10, pp 2532.Google Scholar
139. Blythe, P.A. Comparison of exact and approximate methods for analysing vibrational relaxation regions, JFM, 1961, 10, pp 3347.Google Scholar
140. Blythe, P.A. The effects of vibrational relaxation on hypersonic flow past blunt bodies, Aeronaut Q, 1963, 14, pp 357373.Google Scholar
141. Johannesen, N. H., Zienkiewicz, H.K., Blythe, P. and Gerrard, J.H. Experimental and theoretical analysis of vibrational relaxation regions in carbon dioxide, JFM, 1962, 12, pp 213224.Google Scholar
142. Johannesen, N.H., Zienkiewicz, H.K. and Gerrard, J.H. Further results of the over-all density ratios of shock waves in carbon dioxide, JFM, 1963, 17, pp 267270.Google Scholar
143. Johannesen, N.H., Bird, G.A. and Zienkiewicz, H.K. Theoretical and experimental investigations of the reflexion of normal shock waves with vibrational relaxation, JFM, 1967, 30, pp 5164.Google Scholar
144. Bird, G.A. One-dimensional compression of a collisionless gas, JFM, 1965, 21, pp 183191.Google Scholar
145. Bird, G.A. The equilibrium state of a shock-heated atmosphere, Astrophys J, 1965, 141, pp 14551462.Google Scholar
146. Bhangu, J.K. Shock-tube studies of vibrational relaxation in nitrous oxide, JFM, 1966, 25, pp 817820.Google Scholar
147. Rees, T. Computer calculations of relaxation regions and equilibrium conditions for shock waves with tables for CO2 and N2O, 1968, ARC, R & M No 3472.Google Scholar
148. Rees, T. and Bhangu, J.K. The effects of small quantities of hydrogen, deuterium and helium on vibrational relaxation of carbon dioxide, JFM, 1969, 39, pp 601610.Google Scholar
149. Zienkiewicz, H.K. Wave theory of the Mach-Zehnder interferometer, 1961, ARC, R & M No 3173.Google Scholar
150. Zienkiewicz, H.K. On the formation of white-light fringes in the Mach-Zehnder interferometer, 1968, ARC, R & M No 3532.Google Scholar
151. Rarity, B.S.H. The wall jet on a rotating disc, QJMAM, 1965, 18, pp 455472.Google Scholar
152. Rarity, B.S.H. On the viscous flow in the nose region of a symmetric blunt body in hypersonic flow, JFM, 1966, 26, pp 829839.Google Scholar
153. Stevenson, T.N. The mean flow in the outer region of turbulent boundary layers, 1965, AGARDograph 97, pp 281314.Google Scholar
154. Stevenson, T.N. Inner region of transpired turbulent boundary layers, AIAA J, 1968, 6, pp 553554.Google Scholar
155. Yule, A.J. Two-dimensional self-preserving turbulent mixing layers at different free stream velocity ratios, 1972, ARC, R & M No 3683.Google Scholar
156. Yule, A.J. Spreading of turbulent mixing layers, AIAA J, 1972, 10, p 686.Google Scholar
157. Stevenson, T.N. Some two-dimensional internal waves in a stratified liquid, JFM, 1968, 33, pp 715720.Google Scholar
158. Stevenson, T.N. The phase configuration of internal waves around a body moving in a density stratified fluid, JFM, 1973, 60, pp 759767.Google Scholar
159. Mowbray, D.E. The use of schlieren and shadowgraph techniques in the study of flow patterns in density stratified liquids, JFM, 1967, 27, pp 595608.Google Scholar
160. Mowbray, D.E. and Rarity, B.S.H. A theoretical and experimental investigation of the phase configuration of internal waves of small amplitude in a density stratified liquid, JFM, 1967, 28, pp 116.Google Scholar
161. Mowbray, D.E. and Rarity, B.S.H. The internal wave pattern produced by a sphere moving vertically in a density stratified liquid, JFM, 1967, 30, pp 489495.Google Scholar
162. Thomas, N.H. and Stevenson, T.N. An internal wave in a viscous ocean stratified by both salt and heat, JFM, 1973, 61, pp 301304.Google Scholar
163. Chang, W.L. and Stevenson, T.N. Internal waves in a viscous atmosphere, JFM, 1975, 72, pp 773786.Google Scholar
164. Stevenson, T.N., Chang, W.L. and Laws, P. Viscous effects in lee waves, Geophys Astrophys Fluid Dynamics, 1979, 13, pp 141151.Google Scholar
165. Laws, P., Peat, K.S. and Stevenson, T.N. An interferometer to study density stratified flows, J Phys E: Sci Instrum, 1982, 15, pp 13271331.Google Scholar
166. Nicolaou, D., Liu, R. and Stevenson, T.N. The evolution of thermocline waves from an oscillating disturbance, JFM, 1993, 254, pp 401416.Google Scholar
167. Huang, P.K. The Generation of Internal Waves by an Oscillating Wing in a Pynocline, 2000, PhD thesis, University of Manchester.Google Scholar
168. Law, A.K.O. Numerical Simulations of Internal Waves in Stratified Fluids, 1999, PhD thesis, University of Manchester.Google Scholar
169. Saeedipour, H. R. and Stevenson, T.N. The effects of small changes to the design specification of a jet civil transport aircraft, Aircraft Design, 1998, 1, pp 2541.Google Scholar
170. Ackroyd, J.A.D. A study on the running times in shock tubes, 1964, ARC, CP No 722.Google Scholar
171. Ackroyd, J.A.D. On the laminar compressible boundary layer induced by the passage of a plane shock wave over a flat wall, Proc Cam Phil Soc, 1967, 63, pp 889907.Google Scholar
172. Samuel, T.D.M.A. and Ackroyd, J.A.D. Shock-induced turbulent boundary layers, Appl Sci Res, 1973, 28, pp 161184.Google Scholar
173. Ackroyd, J.A.D. Laminar natural convection boundary layers on near-horizontal plates, Proc Roy Soc A, 1976, 352, pp 249274.Google Scholar
174. Zakerullah, M. and Ackroyd, J.A.D. Laminar natural convection boundary layers on horizontal circular discs, ZAMP, 1979, 30, pp 427435.Google Scholar
175. Owen, Y.J. and Ackroyd, J.A.D. Laminar natural convection boundary layers on horizontal surfaces possessing a circular cut-out, ZAMP, 1992, 43, pp 553566.Google Scholar
176. Ackroyd, J.A.D. On the analysis of turbulent boundary layers on slender cylinders, J Fluids Eng, 1982, 104, pp 185190.Google Scholar
177. Ackroyd, J.A.D. On the steady flow produced by a rotating disc with either surface suction or injection, J Eng Math, 1978, 12, pp 207220.Google Scholar
178. Samuel, T.D.M.A. and Hall, I.M. On the series solution to the laminar boundary layer with stationary origin on a continuous, moving porous surface, Proc Cam Phil Soc, 1973, 73, pp 223229.Google Scholar
179. Ackroyd, J.A.D. Lanchester – The man (The 31st Lanchester Lecture), Aeronaut J, 1992, 96, (954), pp 119140.Google Scholar
180. Ackroyd, J.A.D. Sir George Cayley, the Father of Aeronautics. Part 1. The invention of the aeroplane; Part 2. Cayley’s aeroplanes, Notes Rec Roy Soc Lond, 2002, 56, (2), pp 167181; 56, (3), pp 333348.Google Scholar
181. Ackroyd, J.A.D. The United Kingdom’s contributions to the development of aeronautics; Part 1. From antiquity to the era of the Wrights, Aeronaut J, January 2000, 104, (1031), pp 930.Google Scholar
182. Ackroyd, J.A.D. The United Kingdom’s contributions to the development of aeronautics; Part 2. The development of the practical aeroplane (1900-1920), Aeronaut J, December 2000, 104, (1042), pp 569596.Google Scholar
183. Ackroyd, J.A.D., Axcell, B.P. and Ruban, A.I. Early Developments of Modern Aerodynamics, 2001, Butterworth-Heinemann, Oxford/AIAA, Reston, VA.Google Scholar
184. Hughes, T. Laminar compressible boundary layers with non-uniform wall temperatures, Aeronaut Q, 1971, 22, pp 111.Google Scholar
185. Hughes, T. Some heat transfer measurements in compressible turbulent boundary layers, Aeronaut J, 1973, 77, pp 9498.Google Scholar
186. Tyack, S.C. and Hughes, T. Transmission of a continuous square wave down a pneumatic line, J Mech Eng Sci, 1973, 15, pp 187194.Google Scholar
187. Smith, D. J. and Hughes, T. Some measurements in a turbulent circular jet in the presence of a co-flowing free stream, Aeronaut Q, 1977, 28, pp 185196.Google Scholar
188. Smith, D.J. and Hughes, T. The flow from notched nozzles in the presence of a free stream, Aeronaut J, 1984, 88, pp 7785.Google Scholar
189. Hodgson, J.P A survey of the infra-red radiation properties of carbon dioxide, 1968, ARC, CP No 981.Google Scholar
190. Hodgson, J.P. Non-equilibrium emissivity of carbon dioxide near 4.3µ, 1970, ARC, CP No 1116.Google Scholar
191. Hodgson, J.P. and Hine, R.J. Measurement of the relaxation frequencies of the asymmetric stretching mode of carbon dioxide, JFM, 1969, 35, pp 171183.Google Scholar
192. Hine, R.J. Vibrational equilibrium calculations of properties behind reflected shock waves with tables for CO2 and N2O, 1971, ARC, CP No 1201.Google Scholar
193. Hodgson, J.P. and Johannesen, N.H. Real-gas effects in very weak shock waves in the atmosphere and the structure of sonic bangs, JFM, 1971, 50, pp 1720.Google Scholar
194. Hodgson, J.P. Vibrational relaxation effects in weak shock waves in air and the structure of sonic bangs, JFM, 1973, 58, pp 187196.Google Scholar
195. Hodgson, J.P. The structure of weak shock waves in mixtures of vibra-tionally relaxing gases, 1973, Recent Developments in Shock Tube Research (Bershader, D. and Griffith, W.C. (Eds)), pp 3546, Stanford University Press.Google Scholar
196. Dain, C.G. and Hodgson, J.P. Generation of weak shock waves in a shock tube, Aeronaut Q, 1974, 25, pp 101108.Google Scholar
197. Johannesen, N.H. and Hodgson, J.P. The physics of weak waves in gases, Rep Prog Phys, 1979, 42, pp 629676.Google Scholar
198. Hastings, D.L. and Hodgson, J.P. The formation of an aqueous fog in a shock tube, J Phys D: Appl Phys, 1979, 12, pp 21112122.Google Scholar
199. Mohammad, K. The centred expansion wave in one-dimensional unsteady flow of a gas with vibrational relaxation, QJMAM, 1974, 27, pp 387402.Google Scholar
200. Hornby, R.P. and Johannesen, N.H. The development of weak waves in the steady two-dimensional flow of a gas with vibrational relaxation past a thin wedge, JFM, 1975, 69, pp 109128.Google Scholar
201. Dain, C. G. and Hodgson, J.P. The development of weak waves in the unsteady one-dimensional flow of a vibrationally relaxing gas ahead of an impulsively started piston, JFM, 1975, 69, pp 129144.Google Scholar
202. Kao, J. and Hodgson, J.P. Supersonic flow of a vibrationally relaxing gas past a circular cone, JFM, 1978, 85, pp 519542.Google Scholar
203. Rarity, B.S.H. On the breakdown of characteristics solutions in flows with vibrational relaxation, JFM, 1967, 27, pp 4957.Google Scholar
204. Bellamy-Knights, P.G. Bounds for the drag on a circular cylinder due to a pair of symmetric vortices in the wake, J Fluids Eng, 1973, 95, pp 333334.Google Scholar
205. Bellamy-Knights, P.G. An unsteady two-cell vortex solution of the Navier-Stokes equations, JFM, 1970, 41, pp 673687.Google Scholar
206. Bellamy-Knights, P.G. Unsteady multicellular viscous vortices, JFM, 1971, 50, pp 116.Google Scholar
207. Bellamy-Knights, P.G. An axisymmetric boundary layer solution for an unsteady vortex above a plane, Tellus, 1974, 26, pp 318324.Google Scholar
208. Hatton, L. Stagnation point flow in a vortex core, Tellus, 1975, 27, pp 269280.Google Scholar
209. Bellamy-Knights, P.G. Viscous compressible heat conducting spiralling flow, QJMAM, 1980, 33, pp 321336.Google Scholar
210. Bellamy-Knights, P.G. and Saci, R. Unsteady convective atmospheric vortices, Boundary-Layer Meteorology, 1983, 27, pp 371386.Google Scholar
211. Bellamy-Knights, P.G. and Saci, R. Viscous vortex core generation, Acta Mech, 1987, 67, pp 121127.Google Scholar
212. Bellamy-Knights, P.G. and Hatton, L. A diffusing vortex model of a waterspout, Arch Mech, 1989, 41, pp 651657.Google Scholar
213. Bellamy-Knights, P.G. and Saci, R. Flow between two stationary disks and a rotating shroud, J Computers and Fluids, 1991, 20, pp 7787.Google Scholar
214. Bellamy-Knights, P.G. and Saci, R. Diffusion driven rotating flow in a cylindrical container, Acta Mech, 1998, 126, pp 4557.Google Scholar
215. Bellamy-Knights, P.G., Benson, M.G., Gerrard, J.H. and Gladwell, I. Analytical surface singularity distributions for flow about cylindrical bodies, J Eng Math, 1989, 23, pp 261271.Google Scholar
216. Bellamy-Knights, P.G., Benson, M.G., Gerrard, J.H. and Gladwell, I. Convergence properties of panel methods, Comp Meth Appl Mech and Eng, 1989, 76, pp 171178.Google Scholar
217. Benson, M.G., Bellamy-Knights, P.G., Gerrard, J.H. and Gladwell, I. A viscous splitting algorithm applied to low Reynolds number flows round a circular cylinder, J Fluids Struct, 1989, 3, pp 439479.Google Scholar
218. Bellamy-Knights, P.G. Analytical vortex and source surface singularity distributions for flow about elliptic cylinders, ZAMP, 1993, 44, pp 977987.Google Scholar
219. Bellamy-Knights, P.G. A perturbation method for surface singularity solutions for potential flow, Acta Mech, 1996, 117, pp 8187.Google Scholar
220. Bellamy-Knights, P. G. An image system and surface singularity solutions for potential flow past an elliptic cylinder, IMA J Appl Math, 1998, 15, pp 299310.Google Scholar
221. Pannu, S.S. and Johannesen, N.H. The structure of jets from notched nozzles, JFM, 1976, 74, pp 515528.Google Scholar
222. Hodge, I.S., Smith, D.J. and Johannesen, N.H. Digital, spectral analysis of the noise from short duration impulsively started jets, J Sound Vib, 1982, 82, pp 171179.Google Scholar
223. Smith, D.J. and Johannesen, N.H. The effects of density on subsonic jet noise, 1986, IUTAM Symposium on Aero and Hydro-Acoustics, Springer.Google Scholar
224. Carpenter, P.W. A numerical investigation into the effects of compressibility and total enthalpy difference on the development of a laminar free shear layer, JFM, 1971, 50, pp 785799.Google Scholar
225. Carpenter, P.W. and Johannesen, N.H. An extension of one-dimensional theory to inviscid swirling flow through choked nozzles, Aeronaut Q, 1975, 26, pp 7187.Google Scholar
226. Smith, R. An investigation of supersonic swirling jets, Aeronaut Q, 1973, 24, pp 167178.Google Scholar
227. Smith, R. Hypersonic swirling flow past blunt bodies, Aeronaut Q, 1973, 24, pp 241251.Google Scholar
228. Bloy, A.W. The expansion of a hypersonic turbulent boundary layer at a sharp corner, JFM, 1975, 67, pp 4765.Google Scholar
229. Bloy, A.W. The pressure waves produced by the convection of temperature disturbances in high subsonic nozzle flows, JFM, 1979, 94, pp 465475.Google Scholar
230. Bloy, A.W. The radiation of a sound pulse from a jet nozzle, J Sound Vib, 1985, 99, pp 95109.Google Scholar
231. Bloy, A.W., Lamont, P. J., Abu-Assaf, H.A. and ALI, K.A.M. The lateral dynamic stability and control of a large receiver aircraft during air-to-air refuelling, Aeronaut J, 1986, 90, pp 237243.Google Scholar
232. Bloy, A.W., Ali, K.A.M. and Trochalides, V. The longitudinal dynamic stability and control of a large receiver aircraft during air-to-air refuelling, Aeronaut J, 1987, 91, pp 6471.Google Scholar
233. Bloy, A.W. and Trochalides, V. The performance and longitudinal stability and control of large receiver aircraft during air-to-air refuelling, Aeronaut J, 1989, 93, pp 367378.Google Scholar
234. Bloy, A.W. and Trochalides, V. The aerodynamic interference between tanker and receiver aircraft during air-to-air refuelling, Aeronaut J, 1990, 94, pp 165171.Google Scholar
235. Bloy, A.W., Trochalides, V. and West, M.G. The aerodynamic interference between a flapped tanker aircraft and a receiver aircraft during air-toair refuelling, Aeronaut J, 1991, 95, pp 274282.Google Scholar
236. Bloy, A.W., West, M.G., Lea, K. A. and Jouma’a, M. Lateral aerodynamic interference between tanker and receiver in air-to-air refuelling, J Aircr, 1993, 30, pp 705710.Google Scholar
237. Bloy, A.W. and Jouma’a, M. Lateral and directional stability control in air-to-air refuelling, J Aerospace Eng, 1995, 209, pp 299305.Google Scholar
238. Bloy, A.W. and Khan, M.M. Modelling of the hose and drogue in air-toair refuelling, Aeronaut J, 2002, 106, pp 1726.Google Scholar
239. Bloy, A.W. and Roberts, D.G. Aerodynamic characteristics of the NACA632-215 aerofoil for use in wind turbines, Wind Eng, 1993, 17, pp 6775.Google Scholar
240. Bloy, A.W. and Durrant, M.T. Aerodynamic characteristics of an aerofoil with small trailing-edge flaps, Wind Eng, 1995, 19, pp 167172.Google Scholar
241. Bloy, A.W., Tsioumanis, N. and Mellor, N.T. Enhanced aerofoil performance using small trailing-edge flaps, J Aircr, 1997, 34, pp 569571.Google Scholar
242. Lamont, P. J. Pressures around an inclined ogive cylinder with laminar, transitional or turbulent separation, AIAA J, 1982, 20, pp 14921499.Google Scholar
243. Lamont, P. J. The complex asymmetric flow over a 3.5D ogive nose and cylindrical afterbody at high angles of attack, 1982, AIAA Paper 82-0053.Google Scholar
244. Lamont, P.J. The effect of Reynolds number on normal and side forces on ogive-cylinders at high incidence, 1985, AIAA Paper 85-1799.Google Scholar
245. Lamont, P.J. and Ouyang, Q. Asymmetric flow over cones at high incidence,, 1987, Proc ICFM, Beijing, China.Google Scholar
246. Lamont, P.J. Multiple solutions for aircraft sideslip behaviour at high angles of attack, 1989, AIAA Paper 89-0645.Google Scholar
247. Lamont, P.J. Experimental work on the asymmetric flow over slender bodies at high incidence, 1989, Proc RAeS Conference; Prediction and Exploitation of Separated Flow, London.Google Scholar
248. Lamont, P.J. and Kennaugh, A. Total incidence plane aerodynamics: The key to understanding high incidence flight dynamics?, J Aircraft, 1991, 28, pp 431435.Google Scholar
249. Ackroyd, J.A.D. and Lamont, P.J. A comparison of the turning radii for four Battle of Britain fighter aircraft, Aeronaut J, February 2000, 104, (1032), pp 5358.Google Scholar
250. Crowther, W.J. and Lamont, P.J. A neural network approach to the calibration of a flush air data system, Aeronaut J, 2001, 105, (1044), pp 8595.Google Scholar
251. Hall, I.M. and Suddhoo, A. Inviscid compressible flow past multielement aerofoils, 1984, AGARD CP 365.Google Scholar
252. Suddhoo, A. and Hall, I.M. Test cases for the plane potential flow past multi-element aerofoils, Aeronaut J, 1985, 89, pp 403414.Google Scholar
253. Poll, D.I.A. Transition in the infinite swept attachment line boundary layer, Aeronaut Q, 1979, 30, pp 607629.Google Scholar
254. Poll, D.I.A. Transition description and prediction in three-dimensional flows, 1984, AGARD Rep No 709.Google Scholar
255. Hall, P., Malik, M.R. and Poll, D.I.A. On the stability of an infinite swept attachment line boundary layer, Proc Roy Soc A, 1984, 395, pp 229245.Google Scholar
256. Poll, D.I.A. Some observations of the transition process on the windward face of a long yawed cylinder, JFM, 1985, 150, pp 329356.Google Scholar
257. Mullender, A.J., Bergin, A.L. and Poll, D.I.A. Application of laminar flow control to aero engine nacelles, 1991, Int Conf on Boundary Layer Transition and Control, RAeS, Cambridge.Google Scholar
258. Ford, R.W. and Poll, D.I.A. A parallel processing approach to transition prediction for laminar flow control system design, Scientific Programming, 1995, 4, (3), pp 203217.Google Scholar
259. Gallagher, M.C., Walsh, S.A. and Poll, D.I.A. On the effect of uniform suction on stability and transition in zero pressure gradient, viscous, incompressible flow, Aeronaut J, 1996, 100, (995), pp 143150.Google Scholar
260. Poll, D.I.A. Technical challenges in space vehicle design: Science fiction versus science fact, Proc Man Lit Phil Soc, 1989-90, 129, pp 8197.Google Scholar
261. Poll, D.I.A. Heat transfer to a swept leading edge in hypersonic flow including effects of transition, 1992, IUTAM Symposium on Aerothermochemistry of Spacecraft and Associated Hypersonic Flows, Marseilles.Google Scholar
262. Poll, D.I.A. Hypersonic laminar-turbulent transition and its implications for winged configurations, 1996, AGARD Rep No 813.Google Scholar
263. Han, J. H., Kennaugh, A. and Poll, D.I.A. Visualisation of nonequilibrium dissociating flows, Proc Inst Mech Eng G, 1998, 211, pp 295305.Google Scholar
264. Shahpar, S., Hall, I.M. and Poll, D.I.A. Marching with the parabolised Navier-Stokes equations, Workshop on Hypersonic Flows for Reentry Problems, 1990, INRIA Conference, Antibes.Google Scholar
265. Wright, J.R. Flutter test analysis in the time domain using a recursive system representation, J Aircr, 1974, 11, pp 774776.Google Scholar
266. Hancock, G.J., Wright, J.R. and Simpson, A. On the teaching of the principles of wing bending – torsion flutter, Aeronaut J, 1985, 89, pp 285305.Google Scholar
267. Juang, J.N., Cooper, J.E. and Wright, J.R. An eigensystem realisation algorithm using data correlations (ERA/DC) for modal parameter identification, J Control-Theory and Advanced Technology, 1988, 4, pp 514.Google Scholar
268. Sedhaghatw, A., Cooper, J.E., Leung, A.Y.T. and Wright, J.R. Estimation of the Hopf bifurcation point for aeroelastic systems, J Sound Vib, 2001, 248, pp 3142.Google Scholar
269. Sedhaghat, A., Cooper, J.E., Wright, J. R. and Leung, A.Y.T. Limit cycle oscillation prediction of non-linear aeroelastic instabilities, Aeronaut J, 2002, 106, (1056), pp 2732.Google Scholar
270. Burrows, A. Wright, J. R. and Coote, J. A. Optimal excitation for flutter testing, Proc Inst Mech Eng G, 1996, 209, pp 313325.Google Scholar
271. Wright, J.R., Wong, J., Cooper, J.E. and Dimitriadis, G. On the use of control surface excitation in flutter testing, Proc Inst Mech Eng G, 2003, 217, pp 317332.Google Scholar
272. Hamilton, M.J., Cooper, J.E. and Wright, J. R. Experimental evaluation of various normal mode force appropriation methods, Int J Anal Experimental Modal Analysis, 1995, 10, (2), pp 118130.Google Scholar
273. Wright, J.R., Cooper, J.E. and Desforges, M.J. Normal-mode force appropriation – Theory and application, Mech Systems and Signal Processing, 1999, 13, (2), pp 217240.Google Scholar
274. Al-Hadid, M. and Wright, J.R. Application of the force-state mapping approach to the identification of non-linear systems, Mech Systems and Signal Processing, 1990, 4, (6), pp 463483.Google Scholar
275. Mcewan, M.I., Wright, J.R., Cooper, J.E. and Leung, A.Y.T. A combined modal/finite element analysis technique for the dynamic response of a non-linear beam to harmonic excitation, J Sound Vib, 2001, 243, (4), pp 601624.Google Scholar
276. Carrington, I.B., Wright, J.R., Cooper, J.E. and Dimitriadis, G. A comparison of blade tip-timing data analysis methods, Proc Inst Mech Eng G, 2001, 215, pp 301312.Google Scholar
277. Cayley, G. On aerial navigation, A Journal of Natural Philosophy, Chemistry and the Arts, 1809, 24, pp 164174.Google Scholar
278. Hall, I.M. Aeronautical Engineering at the University of Manchester, Aircraft Eng, 1963, 35, pp 297299.Google Scholar