Heat transfer in a side heated trapezoidal cavity with openings

Abstract

A control volume based numerical study has been carried out on trapezoidal cavity which has formed by inclined left heated wall and insulated bottom horizontal walls. The calculations are performed for Rayleigh numbers varying from 103 to 107 and orientation of heated wall is ϕ=60° and 120°. The results are compared for cases without opening and with different openings of the vertical wall as functions of isotherms, streamfunctions, local and average heat transfer rates. The overall Nusselt number increases with increase of Rayleigh number, but decreases with increase in angle of orientation. The transition region between conduction to convection is existing almost at Ra = 5 × 103. It has been observed that the case having vents at extreme ends exhibits highest heat transfer compared to other cases. The heat transfer is better for the orientation angle of 60°. As compare to uniformly cooled wall, the heat transfer is enhanced by 23%, 39%, 56% and 74% at Ra = 104, 105, 106 and 107 respectively. The power law correlations have been developed between average Nusselt numbers and Rayleigh numbers. Keywords: Natural convection, Inclined trapezoidal cavity, Heat flux, Energy and building, Partially open cavity