The interaction of moving conducting fluids with electric and magnetic fields provides the magnetohydrodynamic (MHD) phenomenon. Based on this principle, MHD pump uses the ldquoLorentz forcerdquo to move fluid. The railgun channel is one important segment in an electromagnetic launcher (EML). As is known, one of the possible ways to increase the EML efficiency is to segment the working channel. For this purpose, MHD flow study is necessary. It is required to have the knowledge of the flow field and the temperature to design an MHD pump. The purpose of this paper is to investigate the effect of the magnetic flux density and current on the flow and the temperature distribution in an MHD pump. To solve the governing differential equations, a finite-difference-based code is developed and utilized. The temperature and velocity are calculated by solving the energy and the Navier-Stokes equations. Results show a maximum value of velocity for different values of magnetic flux density (B). However, the temperature stays almost constant with magnetic field. In addition, as current increases, the velocity and the temperature increase too.