HEAT-TRANSFER AND FLOW CHARACTERISTICS OF AN OBLIQUE TURBULENT IMPINGING JET WITHIN CONFINED WALLS

Experiments were conducted to determine the turbulent heat transfer and flow characteristics of an oblique impinging circular jet within closely confined walls using air as a working fluid. The local temperature distribution on the impingement surface was obtained in detail by a thermocamera using a liquid crystal sheet. A correction to the heat flux was evaluated by using the detailed temperature distribution and solving numerically the three-dimensional equation of heat conduction in the heated section. Two-dimensional profiles of the local Nusselt numbers and temperatures changed with jet angle and Reynolds number. These showed a peak shift toward the minor flow region and a plateau of the local heat transfer coefficients in tile major flow region. The local velocity and turbulent intensity in the gap between the confined insulated wall and impingement surface were also obtained in detail by a thermal anemometer.