Hi, I'm trying to make sense of a wave propagation problem. It's a 1D problem, modelling propagation of density perturbations which travel like waves in a fluid. The problem is governed by the mass and momentum equations and density is related to pressure using the bulk modulus of the fluid. The variables are density ($\rho$), pressure (p) and velocity (v). Temperature (T) is constant. So the waves are essentially due to an interplay between p and $\rho$. The fluid is water. I wanted to know whether the isothermal condition makes physical sense. I read somewhere that the isothermal conditions could be explained by the waves having enough time to exchange heat and maintain a constant T. I am guessing the problem is correct but struggling to understand it physically. Please help, urgent.