화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.41, No.23, 3899-3918, 1998
Pulsative heating of surfaces
Laser repetitive pulse heating is one of the research fields in laser heating of engineering surfaces. The effect of assisting gas jet on the laser heating process is usually omitted in the previous studies. The present study examines the gas jet assisted laser repetitive pulse heating of steel surfaces. The flow and temperature fields are predicted numerically using the control volume approach. The two-dimensional axisymmetric heat conduction equation is solved for the solid substance, while continuity, momentum, energy and equation of state are considered for the impinging air, which is introduced coaxially with the laser beam and orthogonal to the workpiece surface as the assisting gas. The low Reynolds number k-epsilon model is used to account for the turbulence in the flow field. The solid and gas properties are considered as variable. The study is extended to include three pulse types and two gas jet velocities. It is found that the thermal integration for the repetitive pulses of high cooling periods is unlikely and the effect of gas jet velocity is not substantial on the resulting solid side temperature profiles.