Homogeneous Flow

This post is kinda technical and may be relevant to very few. But then it has to be like this. If one still reads on one may understand it.
Today I will talk about two phase flow i.e. flow of liquid + vapor(of the same liq.) in a pipe. Homogeneous flow model is a theory which proposes to quantify the flow process to get numerical values out of it. It assumes that the liquid and vapor states are mixed homogeneously and a pseudo state - a mixture of both of it - is formed in the pipe. The assumption is wrong as it can be felt with our experiences with water and water-vapor in our daily life. All the laws of Fluid mechanics (with slight modification) are assumed to be applicable on this phase. This gives all the parameters like mean velocity, mean density, mean viscosity of the flow, wall friction, Reynolds number.
This modeling looks quite vague in the first look but is very good to start. It gives results of the orders of magnitude close to the actual values obtained by performing experiments. In fact this model works quite good (error of around 30%) in the type of flow in which vapor and liquid are mixed such that vapor form small droplets mixed in bulk of the flowing liquid. This model is also known as fog flow model because of the above formation.