MINOR HEAD LOSS ANALYSIS OF LAMINAR FLUID FLOW IN COMPLEX GEOMETRIES

Abstract

Minor head loss occurs in most hydraulic equipment because the flow is affected by a shape change. Head loss analysis is essential in designing and fabricating hydraulic equipment and systems. In the general case, the evaluation of head losses is challenging and usually done by experimental methods. Recently, the calculation has been more convenient using the computational fluid dynamics (CFD) method. This article employs the finite element method (FEM) to evaluate the local hydraulic losses in complex geometries discretized by unstructured mesh. The method is applied to the laminar flow of Newtonian fluid. First, the code is validated by comparing the numerical solution with experimental data and previous numerical results. The code is then employed to simulate different problems, including a complex geometry that mimics the control valve in hydraulic systems. Simultaneously, the minor loss coefficient is calculated for different Re numbers. From the results, the minor loss coefficient is large for low Re, and can be up to 700 for Re = 10 of complicated geometry. For a high Re, the minor loss coefficient is rapidly decreased and close to the value of a turbulent model.