Computational fluid dynamics has proven itself as a versatile tool to study various urban physics phenomena and develop urban heat island adaptation strategies. This study is based on the development of new parameterization related to aerodynamic and thermal effects of urban vegetation; and their implementation in CFD to study its effectiveness in improving the thermal environment with approximately 100 trees having canopy width/height of 9 m. A more realistic consideration of these parameters is required to improve the quality/accuracy of CFD results. The study results show that vegetation, modeled with these developed parameters (i.e. actual form drag coefficient and variable tree transpiration rate), yields significant variation in micro-climatological results, as causes a reduction of 1.2 K and 0.9 K; 4.0 K and 1.8 K in air temperature and surface temperature respectively. The tree, modeled with the actual form drag coefficient, has highest impact in reducing velocity i.e. upto 0.5 m/sec.

Attempts is being made on developing more advanced and effective techniques for the dissipation of heat in electronic and microelectronic equipment. It is still a main challenge to increase the cooling efficiency by increasing a heat dissipation rate for the performance of microelectronic equipment. The present study deals with a computational numerical analysis of compact heat exchangers, used for the dissipation of heat generated by electrical and electronic components under forced convection. The analysis was done by k- ω model based with shear-stress transport (SST), low Reynolds no. correction to calculate the heat transfer in turbulent flow for inlet velocities ranging from 1 m/s - 6 m/s. To access the increase heat transfer, first the results were validated using experimental data previously conducted by Kai-Shing Yang et al [1] and then the geometry was modified by attaching 9 semi-spherical shapes on each fin. Staggered arrangement of pin fins is used for effective heat transfer. The performance of pin fins was analyzed for a series of frontal velocities ranging from 1-6m/s in a 470mm long fluid domain. The constant amount of 25W heat at base plate was supplied. It is found that the optimum configuration of pin fins using semi-spherical profiles on it significantly increased the heat transfer in terms of heat transfer co-efficient with the negligible amount of pressure lost across the pin fins. This study suggest that the new model used possess the higher heat transferability and a proper mixing of air in pin fins.