Mixed convective laminar flow and the properties of heat transfer within lid driven pentagonal cavity along with heated triangular blockage nearly at the middle of the cavity domain has been numerically analysed with the help of finite element approximation in accordance with Galerkin method. Most of the researchers have been taken square cavity with or without some blockages within the cavity domain. But none of them has been taken the pentagonal cavity as well as triangular blockage. It is to be known how the non-orthogonal sides of a cavity effect the fluid mixing efficiency and heat transfer mechanism. So, this is a unique idea that we have developed in our study. This study can be helpful to know the temperature distribution and cooling efficiency of mixed convection systems such as heat exchangers, cooling of irregularly shaped electronic equipment, microfluidic devices, solar collectors, tissue engineering and drug delivery systems etc. Air with Prandtl numberPr = 0.72 has been considered as the acting fluid within the cavity. Here we have discussed the stream function, isotherms, local and average Nusselt number to clarify the impact of Reynolds number Re, Hartman number Ha and Richardson number Ri upon the heat transfer phenomena inside the cavity domain. Numerical values of local and average Nusselt number have been represented graphically. It is seen that average Nusselt number of the hot and vertical cold cavity walls has been increased gradually with the increase of Ha, Ri and Re. In our present study, we have compared average Nusselt number of hot and vertical cold cavity walls obtained for the presence of blockage and without the blockage. We have seen that, the average Nusselt number Nu avg of the vertical cold cavity wall has been increased to maximum 205.86% for Ri = 10,Ha = 5 due to the presence of the heated blockage as compare to the values of Nu avg without blockage whereas it has been decreased to maximum 58.15% for Ri = 100 andHa = 0. Nu avg of the hot cavity wall has been increased to maximum 125.21% for Ri = 10,Ha = 5 due to the presence of the heated blockage as compare to the values of Nu avg without blockage whereas it has been decreased to maximum 73.36% for Ri = 0.05 andHa = 15.
Sarkar et al. (Thu,) studied this question.