Experimental study on influence of forced vibration of cooling channel on heat transfer instability at atmospheric and quasi-critical pressure

Abstract

Hydrocarbon fuel is used as coolant to cool scramjet by flowing through cooling channels at atmospheric pressure and quasi-critical pressure conditions. The instability of the heat transfer will occur in this process. However, the effect of scramjet vibration on the heat transfer instability is unclear. In order to study the effect of cooling channel forced vibration on the unstable heat transfer performance at trans-crtical pressure, cooling channel heat transfer characteristics under different vibration condition are analyzed. Experimental results show that at atmospheric pressure, cooling channel vibration causes a drastic change in the temperature of the inner wall during unstable heat transfer process, but vibration will not change the fuel bulk temperature oscillation process. As a result, forced vibration can lead to heat transfer deterioration in the gas-liquid two-phase flow. Under the condition of quasi-critical pressure, cooling channel vibration not only change the inner wall temperature, but also influence the fuel bulk temperature. The forced vibration can lead to heat transfer enhancement. High frequency vibration can effectively suppress heat transfer instability and reduces heat transfer fluctuations.