Investigation of Supersonic Shock Phenomena in a Two-Phase (Liquid-Gas) Tunnel

Citation

Eddington, Robert Barnes (1967) Investigation of Supersonic Shock Phenomena in a Two-Phase (Liquid-Gas) Tunnel. Engineer's thesis, California Institute of Technology. doi:10.7907/9RJT-A855. https://resolver.caltech.edu/CaltechETD:etd-06292006-133727

Abstract

Homogeneous two-phase flows of dispersed liquid and gas having gas-to-liquid volume ratios around 1:1 exhibit the characteristics of a continuum flow with a greatly reduced sound propagational velocity that approaches 66 ft/sec at atmospheric pressure, and that is reduced further in value as the square root of the pressure. Flows of such mixtures at velocities in excess of the local velocity of sound can produce shock phenomena similar to that experienced in supersonic gaseous media. A supersonic two-phase tunnel was designed and built with such versatility and precision that normal and oblique shock structures can be photographed and analyzed in the absence of boundary-layer interference. The applicability of the isothermal continuum theory to such flows is confirmed empirically for volume ratios near 1:1, and the theory is mathematically extended for both normal and oblique shocks over a wide range of volume ratios centered about the 1:1 value. Auxiliary flow devices were constructed for the measurement of such difficult flow parameters as the relative phase velocity, local void ratio, coefficient of friction, and stagnation pressure. A general change in the flow model matrix was found at volume ratios approaching 1:1. Pressure gradients and relative phase velocities were correlated with the proposed flow models with generally good agreement. The coefficient of friction measured for supersonic flow was found to be a simple function of the local void ratio. Stagnation pressures measured for a wide range of flow conditions approximate an isentropic relation for a substantial part of the lower velocity spectrum. At higher velocities, the stagnation pressure closely approaches the normal shock plus isentropic slowdown theory. Considerable photographic information pertaining to shock structure and phase movement is obtained over the spectrum of flow conditions with Mach numbers ranging from 2 to 20.

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