STUDY OF MESH INDEPENDENCE ON THE COMPUTATIONAL MODEL OF THE ROLL-UP VORTEX PHENOMENON ON FIGHTER AND DELTA WING MODELS

摘要

A good visualization technique is needed to analyze the flow around the aircraft to see how much innovation can be made to improve the performance of a fighter. The use of water tunnel experiments is one of the solutions to getting a detailed visualization of the flow patterns that occur. However, there is some other information that is difficult to obtain qualitatively, so it requires computational fluid dynamics (CFD) techniques to extract some detailed data mainly related to the airflow around the fighter, such as the occurrence of roll-up vortex phenomena. One of the most important things to note on the use of CFD methods is the need for studies concerning the technique of meshing arrangements and the selection of constitutive equations used to ensure the results of the CFD as accurately as possible. This study will examine the accuracy of using the optimum number of cells on the mesh in obtaining convergent values of lift coefficients (Cl) on the delta wing and the fighter compared to the experimental test of a water tunnel. The results show that the coefficient of lift was converged on the mesh of more than 5 million cells with the error rate below 1%, indicating the optimum value of the mesh.