Heat transfer deterioration of aviation kerosene flowing in mini tubes at supercritical pressures

Abstract

Heat transfer performances of aviation kerosene flowing in mini tubes at supercritical pressures were investigated experimentally and numerically. A ten-species surrogate model with the extended correponding state was used to calculate the thermophysical and transport properties of kerosene and the Re-Normalization Group (RNG) k-ε turbulent model with the enhanced wall treatment was adopted to consider the turbulent effect. The numerical results agree well with the experimental data. Two types of heat transfer deterioration were observed in this paper. The first type of deterioration occurs at the place where the wall temperature exceeds the pseudo-critical temperature, while the second type occurs when the bulk fluid temperature exceeds the pseudo-critical temperature. The effects of several key parameters, such as mass flow rate, heat flux, pressure and inlet temperature on heat transfer deterioration were studied in detail. The results reveal that the heat transfer coefficient increases with increasing mass flow rate and inlet temperature. The effect of heat flux on heat transfer is complicated, while the effect of pressure on heat transfer is insignificant. Heat transfer deterioration can be effectively eliminated by increasing mass flow rate and pressure and decreasing heat flux and inlet temperature. The dramatic variation of thermo-physical properties is the main reason for the heat transfer deterioration.

Numerical Investigation on the Heat Transfer of n-Decane in a Horizontal Channel with Axially Nonuniform Heat Flux under Supercritical Pressure

“…The axial flow acceleration ability is notably enhanced in the near-wall region, which decreases the velocity difference between the near-wall and the core region visibly. Consequently, the turbulence weakens and the heat transfer is deteriorated, which is similar to the results of Huang et al [23] and Jackson et al [26]. That also explains the higher heat transfer resistance in the near-wall region r/R = 0.96-1.00.…”

“…As the fuel temperature exceeds a threshold value, around 800 K for most The HTD of supercritical carbon dioxide draws numerous research interests in the effects of buoyancy lift [14][15][16], micro-scale channels [17][18][19], thermal properties [20], and the working conditions [21,22]. Regarding the supercritical hydrocarbon fuel, two types of HTD of the supercritical hydrocarbon fuel in mini-tubes are observed, where the wall and bulk fluid temperature exceeds the pseudo-critical temperature [23][24][25]. The HTD mechanism is investigated both experimentally and numerically.…”

“…The results show that the HTD is significantly affected by acceleration and the overall average surface heat transfer coefficient increases by 27.5% under the maximum acceleration of 6 g. The HTD suppression method is also a hot topic [53,54]. Huang et al [23] found that HTD can be effectively eliminated by increasing the mass flow rate and pressure and decreasing the heat flux and inlet temperature.…”

Experiments on Heat Transfer of Supercritical Pressure Kerosene in Mini Tube under Ultra-High Heat Fluxes

“…Li et al [26] observed the heat transfer enhancement of aviation kerosene RP-3 when the wall temperature was close to the pseudo-critical value. While in similar experiments [27,28], heat transfer deterioration was observed by several researchers. Except for compound hydrocarbon fuel, the heat transfer of pure hydrocarbon fuels at supercritical pressures was also investigated.…”

Heat Transfer Characteristics of Al2O3-Kerosene and Fe3O4-Kerosene Nanofluids Flowing in a Minitube at Supercritical Pressures

“…Middle zone, where the tube wall temperature is higher than the supercritical temperature. As the near wall fluid has very low density and low viscosity, comparison of numerical data and experimental data [23][24][25][26] for the thermo-physical properties of aviation kerosene at P = 3 Mpa can be found in our previous publication [27]. Good agreement has been reached between the calculated results and experimental data.…”