Flow-Heat Conjugate Numerical Simulation Based on the Time-Domain Method

Abstract

For the popups of the applicability of the time-domain based unsteady flow-heat coupling numerical simulation method in physical problems with time-period characteristic, the cases of the plate convection heat transfer and the hollow blunt-nosed blade with periodic hot spots were conducted through the internal CFD code namely HGFS. The unsteady results are analysed both in the time——domain and the frequency-domain and the main conclusions are as follows:the numerical simulation results of the plate convection heat transfer indicate that the time-scale of heat convention in the fluid domain is 10-3 s order of magnitude, while that of heat conduction in solid domain is seconds. Thus, the disparity of time scale may lead to a sharp increase in the amount of calculation, and even lead to failure of the calculation method based on time-domain. The unsteady numerical simulation of the simplified turbine blade with hot spots shows that, when the sweep frequency increases to 5 times of the original, the first-order amplitude of the temperature wave in the blade decreases to 50.4%, from 0.343 K to 0.173 K, and the corresponding penetration depth decreases to 42.8%, from 5.21 mm to 2.23 mm. The temperature fluctuation amplitude and penetration depth reduce significantly with the increasing of frequency.