Numerical and experimental study of field synergy analysis in water jet impingement based on minimum entropy generation method

Abstract

Most detailed reviews of field synergy principle FSP are mainly focused on numerical approaches, while validating first deduction of FSP experimentally is very rare. Therefore, an experimental analysis is carried out on a simple heated plate surface. Experiments are conducted using infrared thermal-vision system and a professional high-speed camera. The field study concerns the hydrodynamic and water jet velocity ratio based on four different configurations under relatively low jet Reynolds number ranging from 2602 to 6505 and to be optimized by FSP. New analytical equations are developed to verify experimentally the synergy between velocity streamline and temperature field as well as synergy number especially in the mid integral areas where images have clear appearance along the lateral direction of the heated plate. Laminar heat flow field synergy equation is developed based on the minimum entropy generation MEG method, and it is treated for relatively low Reynolds number in order to reduce computational effort and time cost. The new proposed laminar heat synergy optimization equation is deduced by setting irreversibility of heat transfer process under the additional assumption that constraint of thermal generation by mechanism of viscous dissipation is considered. The variation principles with respect to velocity give new Navier–Stokes equation with additional volume force, which is constructed through functional variation of Lagrange multipliers to numerically simulate convective heat transfer. Solving simultaneously the field synergy equations (Fx​, Fy​, Fz) for input constant related to viscous dissipation equal to −1.0E05 will give several synergy flow fields which are followed by gradual increase of entropy generation rate as ratio of H/D increases.