Experimental analysis on mechanism and prediction of thermo-acoustic instability of supercritical RP-3 fuel flowing in a vertical upward channel

Abstract

This article presented an experimental investigation of thermo-acoustic instability of RP-3 (Rocket Propellant 3) aviation kerosene under supercritical pressures in a vertical upward circular channel. The oscillation characteristics of measured parameters were studied. The mechanisms and characteristics of unstable flow and heat transfer were analyzed. The effects of operating parameters, including the inlet fluid temperature, inlet fluid pressure, mass flow rate, and heat flux, on flow and heat transfer instabilities were discussed. The investigation on boundary between stable and unstable conditions under various operating parameters was performed, and two new empirical correlations for critical heat flux prediction were obtained. Results indicate that the coupling relation between the inside-wall temperature, outlet fluid temperature, and inlet-outlet pressure drop is found. The instability of pseudo-film boiling leads to this unstable phenomenon. The critical heat flux increases as the inlet fluid pressure rises, while increases first and then decreases with the increasing Reynolds number of inlet fluid. The proposed correlations work reasonably well in predicting the onset of thermo-acoustic instability.