Simulation of Natural Convection in a Single-Slope Solar Still Desalination Using the Radial Basis Function Method

Desalination systems are very interesting to study in several cases, both experimentally and numerically. The set of equations used in this study consists of Navier–Stokes equations, energyEnergy equations, and concentration equations in primitive variable format. The discretization of the equations is carried out using the implicit Euler method for time derivatives and the radial basis function method for space derivatives. The research was carried out with variations of the Rayleigh numbers (Ra) 104, 105, 106, and 2 × 106. Validation is carried out by comparing the Nusselt number (Nu) from the current modeling results with the results of research from the previous works. The validation results show good accuracy, with an error of 0.4–4.3%. The results show that on isothermal contours, the higher the Rayleigh number (Ra) value, the more clearly the convectionConvection effect can be seen, and the isotherms become curved with the strengthening of convective transport in the cavity.