Seperation Analysis of Strap-ons in the Multi-stage Launch Vehicle Using the Grid Computing Technique

Abstract

A numerical technique for simulating the separation dynamics of strap-on boosters is presented. Six degree of freedom rigid body equations of motion are integrated into the three-dimensional unsteady Navier-Stokes solution procedure to determine the dynamic motions of strap-ons. An automated Chimera overset mesh technique is introduced to achieve maximum efficiency for the relative motion of multiple bodies and each mesh is constructed as multi-block mesh for the representation of the after-body flow. Additionally, a new computing concept, called the Grid computing technique[1,2], is adopted to guarantee sufficient computing resources and a simple load balancing technique is proposed for an efficient computation in the Grid. As a validation of Chimera mesh technique implementation, computed results around the Titan IV launch vehicle is compared with experimental data and, as a validation of base flow analysis, the aerodynamic coefficients of a strap-on booster of KSR-Ⅲ is analyzed numerically. The complete analysis process is then applied to the KSR-Ⅲ, a three-stage sounding rocket researched in Korea. From the analyses, the base flow effect on separation motions of strap-on boosters are investigated and the different aerodynamic characteristics of inviscid and viscous flows at every time interval are examined. In addition, a guidance map of the jettisoning forces and moments for a safe separation is presented from various simulations of separation phenomena with different jettisoning conditions.