Published online by Cambridge University Press: 28 March 2006
The Hartmann oscillator problem is studied using the hydraulic analogy between compressible gasdynamics and incompressible flows with a free surface. Extensive photographs, taken of the oscillator in order to visualize the periodic flow, show that qualitative features of the flow agree well with the observations made with a cavity in an air jet.
The construction and operation of the water channel built and used at the University of California at Los Angeles for this study is also described. Continuous ‘shooting’ water flow was found to be analogous to supersonic isentropic gas flow; a static depth of approximately ¼ in. of water appeared to be satisfactory. It seems that the most valuable aspect of the hydraulic analogy is its ability to easily present excellent visualization of flow phenomena, both steady and unsteady.