机室真空度对高速土工离心机风阻和环境温度影响的数值研究

目的 揭示机室真空度对高速离心机风阻和环境温度的影响机制和规律。方法 基于多参考坐标系计算方法，开展离心机环形机室的三维流动传热数值模拟。结果 在本文的研究范围内，随着机室真空度的下降，离心机风阻功率单调降低，相对于常压环境，当机室真空度降低为5、30 kPa时，风阻功率分别降低超过90%和60%。机室真空度的降低，一方面引起黏性耗散产热的减弱，另一方面也弱化了机室表面对流换热和机室空气的传热能力，体现出复杂的环境温度影响机制。相对于常压环境，机室真空度为5、30 kPa时，离心机室环境最高温度分别降低约24.7、9.4 K。结论 在本文的研究参数范围内，降低机室真空度可以有效降低环境温度，且在真空度降低至10 kPa以下时，降温幅度更为明显。

Effects of Cavity Vacuum Degree on Wind Resistance and Thermal Environment of High-speed Geotechnical Centrifuge

Three-dimensional flow and heat transfer inside the circular cavity wherein centrifuge works were numerically studied with the uses of multi-reference frames (MRF) method, to illustrate the effects of Cavity Vacuum Degree on wind resistance and surrounding temperature of high-speed centrifuge. Under the present research conditions, the results show that with the decrease of vacuum degree, the wind resistance is decreased monotonously. With respect to normal pressure environment, the wind resistance power is decrease more than 90% for vacuum degree of 5 kPa, and 60% for vacuum degree of 30 kPa, respectively. The reduction of vacuum degree leads to the weakening of viscous dissipation and heat generation, but also leads to the weakening of convective heat transfer on the surface of the cavity and the heat transfer ability of the air, which reflects the complex environmental temperature influence mechanism. With respect to normal pressure environment, the maximum temperature in the centrifuge cavity is decreased about 24.7 K for vacuum degree of 5 kPa, and 9.4 K for vacuum degree of 30 kPa, respectively. Under the present research conditions, Decreasing vacuum degree can effectively reduce the ambient temperature, and the temperature drop will be more obvious when vacuum degree is lowered to 10 kPa.