Numerical study of heat transfer by impinging jet with inlet temperature-field excitations using a pseudo-sinusoidal function

摘要

In this article, jet's inlet temperature field is excited and the effect on heat transfer at the target wall after impingement is investigated. Jet's inlet temperature is excited according to a clipped pseudo-sinusoidal function, which approaches a step-function shape. In all cases, jet's Reynolds number based on bulk inlet velocity is 23,000 and a jet's outlet-to-wall distance is 2. Jet is excited at two different amplitudes which are set as 36.2 and 4.76% of the bulk inlet temperature. Also the thermal field of jet is modulated with three different frequencies corresponding to the preferred mode of jet. All Simulations are done in ANSYS CFX using scale-adaptive-simulation model. It is found that amplitude of temperature field excitation is a major factor for improving the heat transfer. The fluid is air in all investigations.