Numerical simulations of heat transfer in plane channel flow

TL;DR

This paper develops and implements a new analytical TKE profile UDF in Fluent to improve turbulence modeling accuracy in plane channel flow simulations, validated against DNS data.

Contribution

A novel analytical TKE profile UDF was created and integrated into Fluent to enhance turbulence predictions near walls in channel flow simulations.

Findings

Accurate TKE profiles achieved with the new UDF.

Validated simulation results against DNS data at Reτ=150.

Improved prediction of turbulence characteristics in heated channel flows.

Abstract

Reynolds-averaged Navier-Stokes (RANS) turbulence models (such as k-\epsilon models) are still widely used for engineering applications because of their relatively simplicity and robustness. In fully developed plane channel flow (i.e. the flow between two infinitely large plates), even if available models and near-wall treatments provide adequate mean flow velocities, they fail to predict suitable turbulent kinetic energy "TKE" profiles near walls. TKE is involved in determination of eddy viscosity/diffusivity and could therefore provide inaccurate concentrations and temperatures. In order to improve TKE a User Define Function "UDF" based on an analytical profile for TKE was developed and implemented in Fluent. Mean streamwise velocity and turbulent kinetic energy "TKE" profiles were compared to DNS data for friction Reynolds number Re\tau = 150. Simulation results for TKE show accurate profiles. Simulation results for horizontal heated channel flows obtained with Fluent are presented. Numerical results are validated by DNS data for Re\tau = 150.