Modeling and Simulation of Impinging Jet

Abstract

The present work is related to Finite Volume Method based 2D and 3D computational study of Impinging of Jet. The study is carried out using FLUENT software. To reduce the 2D computational time, a symmetry condition is applied. Based on 3D simulation result analysis it was found that SST k-ω gives better results as compared RNG k-ԑ and Standard k-ԑ models. Results of 2D and 3D simulations are validated with numerical and experimental work and variations are found within 10%. Impinging plate in case of 3D simulations is kept at constant temperature whereas constant heat flux boundary condition is applied in case of 2D simulations. Nozzle outlet flow conditions is set as fully developed flow for 3D simulations and constant nozzle inlet velocity for 2D simulations. It is suggested to use 3D simulations as compared to 2D simulations as in case of 2D simulations due to assumption actual mass flow rate is not achieved. Preliminary study revealed that maximum heat transfer is achieved at the stagnation point and it decreases as moving away from this point. Thus minimum temperature and maximum Nu is achieved at the stagnation point. The parametric study is carried out by varying in nozzle to plate distance (H/D ratio) and Reynolds number. Based on study it is observed that increase in H/D ratio increases heat transfer and increase in Reynolds Number heat transfer increases up to 20000 and after that it decreases. Such behaviour needs further investigation. For small H/D ratio minimum temperature is achieved at slightly offset position from the stagnation point however this variation is not found for high H/D ratio.