Papers by Author: Vahid Golkarfard

Abstract: A numerical simulation procedure for studying deposition of aerosol particles in a laminar convection flow of radiating gas over a backward-facing step including the effect of thermal force is developed. In the gas flow, all of the heat transfer mechanisms consisting of conduction, convection and radiation take place simultaneously. Behavior of solid particles is studied numerically based on an Eulerian–Lagrangian method. Two dimensional Navier-Stokes and energy equations are solved using CFD techniques, while the radiating transfer equation (RTE) is solved by discrete ordinate method (DOM) for calculating radiative heat flux distribution. The objective of this research is to study the effect of Reynolds number variation and also radiation on thermophoretic deposition of particles. Numerical results show a decrease in deposition percent by increasing in Reynolds number and the radiation effect is negligible. The results are compared with the existing experimental and numerical data and good agreement is found.

Abstract: Buildings are one of the most important energy consumers in the world. High temperature gradients in heating systems can cause the increase of heat loss of the envelopes during the cold season and consequently increase the energy consumption. Floor heating systems has shown that they can generate lower temperature gradients in compare with other convective heating systems. In present study, the CFD simulation is done for a 3-D room and the required energy to achieve the thermal comfort in a room is calculated. The height of the room is changed and the energy loss of the room is calculated for both systems. Results showed that as the height doubles, the wall heat loss for radiator system almost doubles but for the floor heating system it was about 60 percent. This impressive result can recommend the floor heating systems for working areas with tall ceilings.