Heat transfer and flow structures of supercritical n-decane in a regenerative cooling channel loaded with non-uniform heat flux

Abstract

A harsh and complex thermal environment in the combustor threatens safe working of scramjets. In this study, heat transfer and flow structures of supercritical n-decane under 3 MPa in a regenerative cooling channel loaded with non-uniform heat flux distributions are investigated, including uniform, sinusoidal, increased, and decreased heat flux distributions. A verified k–ω SST turbulence model was employed, and a corresponding mesh independence study was performed. From this work, the fluid temperature at the outlet of the heated channel is only determined by the averaged heat flux, and all the regenerative cooling channels achieve the same temperature although loaded with different heat flux distributions. Compared with the fluid temperature, the wall temperature distribution is more sensitive to the variations of heat flux distribution. The regenerative cooling channels loaded with the sinusoidal heat flux distributions exist in several high-temperature regions, and the channel loaded with linear distributions changes the trend of temperature distribution. A larger temperature gradient is found in the regenerative cooling channel wall with a lower thermal conductivity. This work provides a good insight into the characteristics of the flow and temperature field of regenerative cooling channels loaded with non-uniform heat flux considering the effect of conjugate heat transfer.

Heat Transfer and Flow Structure Characteristics of Regenerative Cooling in a Rectangular Channel Using Supercritical CO2

“…Using fuel as the coolant, regenerative cooling is regarded as being an effective and reliable cooling method with a lot of channels arranged inside the combustor wall [28,29], as shown in Figure 2. The fuel flows through the channels absorbing excess heat from combustion chambers and then enters the chamber to proceed with the combustion process [30]. Many works have been conducted to investigate the cooling performance of regenerative cooling using supercritical hydrocarbon fuel in terms of effects of nonuniform heat flux [30][31][32], flow pattern [33] and acceleration and buoyancy [34][35][36][37][38].…”

“…The fuel flows through the channels absorbing excess heat from combustion chambers and then enters the chamber to proceed with the combustion process [30]. Many works have been conducted to investigate the cooling performance of regenerative cooling using supercritical hydrocarbon fuel in terms of effects of nonuniform heat flux [30][31][32], flow pattern [33] and acceleration and buoyancy [34][35][36][37][38]. Liu et al [30] investigated the heat transfer performance and flow structure of supercritical In addition to fundamental research, many researchers also performed investigations of supercritical CO 2 applied in heat exchangers [19][20][21], heat sinks [21][22][23] and other industrial devices [24][25][26].…”

“…Many works have been conducted to investigate the cooling performance of regenerative cooling using supercritical hydrocarbon fuel in terms of effects of nonuniform heat flux [30][31][32], flow pattern [33] and acceleration and buoyancy [34][35][36][37][38]. Liu et al [30] investigated the heat transfer performance and flow structure of supercritical In addition to fundamental research, many researchers also performed investigations of supercritical CO 2 applied in heat exchangers [19][20][21], heat sinks [21][22][23] and other industrial devices [24][25][26]. Chu et al [21] carried out experiments based on a supercritical CO 2 -water experiment platform to test the thermohydraulic performance of a printed circuit heat exchanger.…”

“…Many works have been conducted to investigate the cooling performance of regenerative cooling using supercritical hydrocarbon fuel in terms of effects of nonuniform heat flux [30][31][32], flow pattern [33] and acceleration and buoyancy [34][35][36][37][38]. Liu et al [30] investigated the heat transfer performance and flow structure of supercritical n-decane in a rectangular channel under nonuniform heat flux. The results revealed that the wall temperature distribution was sensitive to the heat flux distribution while the outlet temperature was not affected by nonuniform heat flux.…”