Evaluation of axial velocity and wall pressure models for nozzle bench mark using computational fluid dynamics

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Computational Fluid Dynamics (CFD) was used for the analysis of food and drug administration (FDA) benchmark study for biomedical flow transition. An idealized medical device is presented within this thesis and the CFD predictions of pressure and velocity are compared against experimental measurements of pressure and velocity. Fluid flow transition considered were Re=500, Re =2000, and Re=6500 and four simulation models of laminar, k-omega, k-omega SST and k-epsilon based on inlet throat Reth.= 500, 2000 and 6500. K-omega SST used for mesh independence determination for 0.0008, 0.0004 and 0.0002 element sizes showed good matched velocity 5.9m/sec with 0.0004 and 0.0002. Axial velocity at centerline for Reth = 500, 2000 and 6500 at line X =0, showed maximum difference of 77.4% for velocity at centerline 0.08m and 19% for wall pressure at -0.09m suddenly expansion at laminar region Reynolds number 500. Besides, 65.6% and 17.2% were obtained at Re =2000, which agrees with the CFD simulations and experimental measurements. Nevertheless, Re = 6500 models were in good agreement at 49.6% velocity centerline and 8.10% pressure drop, except in laminar legion. Also, downstream of simulation of Reth =6500, other models disappeared which demonstrated K-epsilon model best at Reynolds number turbulent region. Categorically, wall pressure showed negligible axial pressure gradient at centerline with drop in normalization argument of experimental data from 0 to -120N/m2 counterbalanced at Reth = 500. This deduction could be drawn by disparity of pressure transducer in entire experiment data run.