This paper uses numerical simulation to study laser energy deposition near a wall. Local thermodynamic equilibrium conditions are assumed to apply. The simulations solve the compressible Navier-Stokes equations using a finite volume based numerical method. Thermodynamic and transport properties of air are computed as functions of temperature and pressure. A predictor-corrector based shock capturing scheme is incorporated to account for the strong shock waves. Effects of orientation of energy deposition, maximum temperature of the energy deposition region, length of the energy deposition region L and distance from the wall d have been studied. The values of L and d used in the simulations are 1 and π/2. Vertical energy deposition results in symmetric reflection from the wall. The reflected shock wave is weak and does not affect the roll-up process as it passes through the core. Horizontal energy deposition results in asymmetric reflection from the wall. Also in this case the reflected shock wave is much stronger and does momentarily affect the core roll-up process as it passes through the core. However as it goes past the core the velocity induced in the vertical direction by the following expansion region is much smaller compared to the core axial velocity from right to left. So symmetry is restored about the laser axis and the core eventually rolls up producing the characteristic vortex ring in this case as well. Increasing T_0 results in stronger initial gradients that drive the flow and so shock formation, propagation and core roll-up become faster. Changing L keeping T_0 constant does not affect the initial gradients in the flow field. However, if d is also kept constant, then d/L decreases with increase in L. As a result, for a 2L simulation the wall seems to be relatively closer and the shock wave is still tear-drop shaped as it reaches the wall while for a L/2 simulation the wall seems relatively further away and the shock wave becomes spherical as it reaches the wall.
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