Abstract Inductively-heated solid particles dispersed within a decaying isotropic turbulent carrier gas are investigated via Direct Numerical Simulations (DNS). The multiphase simulations account for the compressibility and temperature-dependent viscosity effects of the carrier gas. We develop a semi-empirical model for solid particle heating through hysteresis and Joules mechanisms as these dispersed particles are inductively heated by an external high-frequency alternating magnetic field. The present study focuses on the characteristic time scales of the induction heating and thermal transport of the gas and their modulating effects on the turbulence. We show that the growth of the Kolmogorov length scale is due to a simultaneous increase in viscosity and decrease in the dissipation rate. The temperature-dependent viscosity of the gas leads to a faster decay of the gas turbulent kinetic energy, mainly due to a decrease of energy at intermediate wavenumbers. The evolution of the gas and particle thermal fluctuations are inversely correlated based on the relative thermodynamic timescales. By investigating the change in the temperature spectrum, two regimes could be identified. A first regime arises as the thermal fluctuations increase in time and is defined by a monotonic increase of thermal energy in the low wavenumber range; as the thermal fluctuations decrease in the second regime, the decay occurs over the entire spectrum. Furthermore, aggressive heating set by lower induction heating timescales results in a decrease in particle clustering whereas the particle thermal response time did not show any effect.

中文翻译：

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湍流中分散金属颗粒的感应加热

摘要 通过直接数值模拟 (DNS) 研究了分散在衰减的各向同性湍流载气中的感应加热固体颗粒。多相模拟考虑了载气的可压缩性和随温度变化的粘度效应。我们通过磁滞和焦耳机制开发了固体颗粒加热的半经验模型，因为这些分散的颗粒被外部高频交变磁场感应加热。本研究的重点是气体的感应加热和热传输的特征时间尺度及其对湍流的调节作用。我们表明 Kolmogorov 长度尺度的增长是由于粘度的增加和耗散率的降低。气体随温度变化的粘度导致气体湍流动能衰减更快，这主要是由于中间波数处的能量减少。基于相对热力学时间尺度，气体和粒子热波动的演变呈负相关。通过研究温度谱的变化，可以确定两种状态。第一种状态随着热波动随时间增加而出现，并由低波数范围内热能的单调增加定义；随着第二个区域的热波动减小，衰减发生在整个光谱中。此外，通过较低的感应加热时间尺度设置的积极加热会导致颗粒聚集减少，而颗粒热响应时间没有显示任何影响。