Response surface methodology for optimization of confined laser ablation propulsion design

The reflection of shockwaves for the confinement of plasma from semispherical-shaped external cavities of metallic and non-metallic material was investigated to study the effect of confined geometries for laser ablation propulsion. Optimization of variables and constants of the proposed propulsion model measured the best values of propulsion parameters, which may help later in improving the efficiency of the system. Response surface methodology (RSM) is a popular statistical method, for optimization to improve the performance of the system. In the present work, RSM was used for the determination of optimum values of laser ablation propulsion parameters for different variables. Laser ablation propulsion parameters were studied for Aluminum, Silver, and Gold samples at different fluence values and cavity diameter sizes. A pulsed Nd-YAG (1064 nm wavelength) laser was used to ablate the sample. The effect of cavity size, cavity material, and fluence were studied on propulsion parameters i.e. coupling coefficient, specific impulse, and Thrust by employing the RSM model. Responses were calculated for both; individual and interaction terms. Optimized values of Coupling coefficient, Specific impulse, and thrust were obtained using contour plots.