A new entry is computed, molar flow rate. Then, the temperature and viscosity of the combined streams are estimated by using molar summations. Definitive Calculations Refer to the Definitive Pipe Sizing formula . The equation cannot be rearranged to solve for one pressure given the other. Therefore, the solution is iterative.
Modern spreadsheets have an equation solver feature that permits iterative solutions to equations.
In VentManifold , the Definitive Sizing formula is solved in a Visual Basic subroutine to model the entire example manifold. Sizing them is straightforward but can be time consuming. It is important to realize that high pressure drops in the piping require that the iterative formula for compressible flow be used. This is the basic data needed for chemengsoftware's VentManifold spreadsheet template. The material balance is completed by summing branches into subheaders, and subheaders into the discharge header.