Evaluation of errors on the CFD computation of air flow and heat transfer around the human body

Abstract

A detailed computer aided design model representing a female human body was created from a 3-D scan of a full scale thermal manikin. The sensible heat losses due to convection and radiation for a person seated in a rectangular room were calculated using CFD simulations, as well as the parameters characterizing the flow around the body including air velocity and temperature. The accuracy of numerical results was evaluated in terms of the physical approximation errors, namely inlet boundary conditions and turbulence models, and spatial discretization errors due to the number of grid elements and grid refinement near solid surfaces. Results were compared to published data from two tests performed in conditions that portrayed the CFD simulations. The use of: a mixed turbulence model between k–ɛ, for zones away from solid surfaces, and k−ω, for zones close to solid surfaces; values of the dimensionless y+ parameter inferior to 5 jointly with a low-Reynolds method to model the flow in the near-wall region of the human surface and inlet non-uniform boundary profiles for temperature, velocity and turbulence intensity, leaded to good agreement with experimental results, with a global mean relative error of the order of 7%, with a standard deviation of 4%, in terms of convective and radiative heat flux between the human body and the thermal environment.