Numerical investigation of jet impingement heat transfer and fluid flow characteristics for 70° apex angle conical surface.

The numerical analysis for concentric jet impingement to the concave surface of the cone is presented in this article. The influence of different parameters are judged based on the non-dimensional heat transfer coefficient Nusselt number. Different parameters like: jet diameter, jet Reynolds number and L/D were considered for heat transfer analysis and to get optimal combination. Reynolds number was changed from 29,000 to 82,000 by changing the velocity of fluid and keeping other parameters unaltered. L/D was changed from 3 to 9.2 by changing 'L' keeping diameter constant and three pipe diameters, 10, 14 and 20 mm were considered for analysis. Simulations were carried out in ANSYS-Fluent software using finite volume method. Numerical results of local Nusselt number is compared with experimental results for validation of numerical solver. Contours of velocity, static pressure and turbulence intensity (TI) and local static pressure along slant edge of the cone is also presented from converged numerical simulation to support heat transfer observation. From the numerical result it is observed that there is insignificant influence of jet diameter on Nusselt number at identical numerical condition. Nusselt number decreases with increase in the L/D and the effect is noticeable near the apex and away from the apex curves for local Nusselt number merges with each other for different L/D. There is 10–20% enhancement in the local Nusselt number near the impingement region with reduction in the L/D from 9.2 to 3.0. Nusselt number increases with increase in the jet Reynolds number. Jet is able to reach closer to the apex hence there is slow moving fluid very near the apex of the cone. Pressure is maximum near the apex of the cone and TI is minimum near the apex of the cone. [ABSTRACT FROM AUTHOR]