Computational modeling in ASHRAE applications requires a level of confidence in the results. This presentation looks at a Verification and Validation of a surface condensation CFD model. The V&V was comprised of a comprehensive procedure for minimizing errors and comparing simulations to a benchmark experiment. The analysis is an assessment of the numerical uncertainty derived from a grid convergence study, an input analysis, a report of experimental uncertainty, and source of unqualified modeling. The total validation uncertainty is calculated for three measured parameters. Simulation results were found to match experimental data within the uncertainty of the validation.

The difficulty and cost associated with detailed measurements of various parameters at a variety of points in a room make CFD a good alternative if CFD results can be believed. This series of simulations modeled a simple case of a thermal manikin in a room with mixing ventilation. The results of these simulations were then compared to existing experiments. Simulations were conducted using different CFD programs, grids, turbulence models, manikin models, and by different users. The study provides insights on what is the current CFD modeling accuracy that one can achieve, believe, and will need for practice.

The CFD is an effective method for investigating air distribution and thermal conditions in large industrial buildings. CFD computing cost is a major concern for industrial simulation, in which CFD grid number plays a dominant role. The mesh type and size are critical on determining the cost of computation and the accuracy of the numerical results. The study uses several different industrial applications to analyze the influence of grid on CFD prediction. The research provides some guidelines on how to control the grid quality to obtain a reasonable accuracy while shorten the computing time for industrial applications