TY - JOUR T1 - Numerical study of aerodynamic drag reduction of blunt nose with hybrid of spike and axial and lateral jet injection TT - مطالعه عددی کاهش درگ آیرودینامیکی دماغه‌ پخ با ترکیب اسپایک و تزریق جت محوری و عرضی JF - mdrsjrns JO - mdrsjrns VL - 16 IS - 7 UR - http://mme.modares.ac.ir/article-15-11115-en.html Y1 - 2016 SP - 133 EP - 142 KW - Aerodynamic Drag reduction KW - Blunt nose KW - Numerical analysis KW - Jet injection KW - Spike N2 - One of the mainchallenges existing in the field of missile aerodynamics is how to reduce the aerodynamic drag of aerospace vehicles through different mechanisms. Thus far, many investigations have been performed to determine the performance and influence of various parameters on the effectiveness of these mechanisms. The challenge particularly is more pronounced in missiles with a blunt nose. The aim of this study is to reduce the aerodynamic drag of such missiles using hybrid employment of mounted spike at the stagnation point of the nose in addition to jet injection at different positions on the spike. To this aim, spike and jet injection configurations are extracted from the literature. Jet injection is considered in the sonic regime and perpendicular to the surface of spike. All analyses are performed using Fluent software along with Navier-Stokes equations for compressible and three-dimensional flow in both steady and unsteady states considering free stream at a Mach number of 1.89 and different angles of attach. Since the numerical simulation of these models requires high processing speed and memory, parallel processing system is employed. Additionally, structure grid and κ-ω -SST turbulence models are utilized. Results indicated that a significant drop in the drag is achieved using the hybrid utilization of jet injection and spike. M3 ER -