Axial steady free surface jet impinging over a flat disk with discrete heat sources

A free jet of high Prandtl number fluid impinging perpendicularly on a soli d substrate of finite thickness containing small discrete heat sources on t he opposite surface has been analyzed. Both solid and fluid regions have be en modeled and solved as a conjugate problem. Equations for the conservatio n of mass, momentum, and energy were solved taking into account the transpo rt processes at the solid-liquid and liquid-gas interfaces. The shape and l ocation of the free surface (liquid-gas interface) was determined iterative ly as a part of the solution process by satisfying the kinematic condition as well as the balance of normal and shear forces at this interface. The nu mber of elements in the fluid and solid regions were determined from a syst ematic grid-independence study. A nonuniform grid distribution was used to adequately capture large variations near the solid-fluid interface. Compute d results included velocity, temperature, and pressure distributions in the fluid, and the local and average heat transfer coefficients at the solid-f luid interface. Computations were carried out to investigate the influence of different operating parameters such as jet velocity, heat flux, plate th ickness, and plate material. Numerical results were Validated with availabl e experimental data. It was found that the local heat transfer coefficient is maximum at the center of the disk and decreases gradually with radius as the flow moves downstream. The thickness of the disk as well as the locati on of discrete sources showed strong influence on the maximum temperature a nd the average heat transfer coefficient. (C) 2000 Elsevier Science Inc. Al l rights reserved.