Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-25T19:23:29.787Z Has data issue: false hasContentIssue false
  • English
  • Français

Measurement of the Mean Pressure Distribution About a Double-wedge Strut in Turbulent Shear Flow

Published online by Cambridge University Press:  07 June 2016

J T Turner ,
M H Turner  and
K J Williams
J T Turner
Affiliation:
Simon Engineering Laboratories, University of Manchester
M H Turner
Affiliation:
Simon Engineering Laboratories, University of Manchester
K J Williams
Affiliation:
Associated Octel Company, Bletchley
Get access

Summary

Surface pressure distributions have been measured on a cylinder with a double-wedge cross section in a two-dimensional channel flow. The flow is sheared in the direction of the cylinder axis, using a grid of parallel wires with variable spacing, in order to simulate the type of geometry and velocity variation which occur for annulus support struts in turbomachines. The strut had a 38° included angle at the leading and trailing edges and an aspect ratio of 1.33 based on the maximum thickness. This was fixed between the parallel walls of a rectangular wind tunnel with end leakage eliminated. Surface pressure distributions were measured over a Reynolds number range of 0.5 × 105 to 1.5 × 105 for three different shear flow conditions. Despite the presence of sharp edges at the mid-chord position, delayed boundary-layer separation beyond the plane of maximum thickness has been found for sufficiently high spanwise shear in the upstream flow. Surprisingly, therefore, some similarity with previous results for struts of circular cross section appears to exist. The influence of the shear flow conditions on the pressure drag force has been determined by numerical integration of the data. Only a slight dependence on the upstream flow conditions is found, although the effect of secondary velocity components may still be observed if the spanwise variations in the local drag force are examined.

Type
Research Article
Information
Aeronautical Quarterly , Volume 25 , Issue 3 , August 1974 , pp. 155 - 364
Copyright
Copyright © Royal Aeronautical Society. 1974

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 Hawthorne, W R, The secondary flow about struts and airfoils. Journal of the Aeronautical Sciences, Vol 21, p 588, 1954.Google Scholar
2 Roshko, A, On the drag and shedding frequency of two-dimensional bluff bodies. NACA TN 3169, 1954.Google Scholar
3 Bishop, R E D, Hassan, A Y, The lift and drag forces on a circular cylinder in a flowing fluid. Proc Roy Soc, Series A, Vol 277, p 32, 1964.Google Scholar
4 Bearman, P W, On vortex street wakes. Journal of Fluid Mechanics, Vol 28, p 625, 1967.Google Scholar
5 Livesey, J L, Turner, J T, The generation of symmetrical duct velocity profiles of high uniform shear. Journal of Fluid Mechanics, Vol 20, p 201, 1964.Google Scholar
6 Turner, J T, Williams, K J, The effect of spanwise velocity distribution on the drag of short struts. Paper 31, Proceedings of a Symposium on Internal Flows, University of Salford, 1971.Google Scholar
7 Williams, K J, PhD thesis, Department of Engineering, University of Manchester, 1972.Google Scholar
8 Livesey, J L, Turner, J T, Glasspoole, W F, The decay of turbulent velocity profiles. Proceedings, Institution of Mechanical Engineers, Vol 180, part 3J, p 127, 1965.Google Scholar
9 Dalton, C, Masch, F D, Influence of secondary flow on drag force. Journal of Engineering Mechanics, American Society of Civil Engineers, p 1249, 1968.Google Scholar
10 Delaney, N K, Sorensen, N E, Low speed drag of cylinders of various shapes. NACA TN 3038, 1953.Google Scholar
11 Donoughe, P L, Prasse, E I, Pressure distributions about finite wedges in bounded and unbounded subsonic streams. NACA TN 2942, 1953.Google Scholar
12 Maskell, E C, A theory of blockage effects on bluff bodies and stalled wings in a closed wind tunnel. ARC R & M 3400, 1965.Google Scholar