Application of a pdf-Turbulence Model to the Heat Transfer of Supercritical Water
The present work on turbulence modelling emphasizes on the special fluid-dynamic characteristics of fluids at supercritical pressure, I.e. The nonlinear dependency of the fluid properties on the local, instantaneous temperature or enthalpy of the turbulent flow. Our approach introduces a physically meaningful assumption about the amplitude and frequency spectrum of the turbulent temperature fluctuations, which is parameterized by using a Gaussian probability density (filter-)function (pdf-model). The model takes these average or mean properties on physical grounds in contrast to other models, in which the fluid properties are simply determined at the local, average temperature or enthalpy. In our approach the local turbulence level is taken into account as a model parameter. Our new pdf-model is tested for various cases of supercritical heat transfer of pipe flows to water, using a semi-analytical method, in which the one-dimensional momentum and energy equations for turbulent flows are integrated numerically. Quasi-fully developed flow is assumed, buoyancy is not considered. Good agreement with various experiments performed by other authors is achieved. The present results are independent of a particular CFD-code, numerical grid or convergence criterion. Our pdf-model can be implemented as a modification of existing turbulence models into any CFD code.
Supercritical pressure heat transfer turbulence model probability density function pdf
Eckart Laurien Yu Zhu
University of Stuttgart, Institute for Nuclear Technology and Energy Systems (IKE) Pfaffenwaldring 31, D-70550 Stuttgart, Germany
国际会议
上海
英文
1506-1522
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）