Large-eddy Simulation Of Turbulent Flow With Heat Transfer In A Heated Vertical Tube

摘要

Detailed simulations of fluid flow and heat transfer can significantly improve the optimization of reactor design and operation. Such simulations can be performed with computational fluid dynamics (CFD) codes. The direct numerical simulation (DNS) of fluid flow and heat transfer at large Reynolds numbers and for system size-scales of engineering interest are not still computationally practical. RANS (Reynolds averaging of the Navier-Stokes equations) turbulence models provide adequately accurate solutions for many engineering problems at a reasonable computational cost. However, there is no single RANS model of universal applicability, and in many important applications the RANS predictions of flow distributions, heat transfer coefficients, and thermal mixing can be significantly off. LES (large eddy simulation) and coarse DNS models of turbulence are the closest approximations to DNS and significantly more accurate than RANS models.