Structural optimization of a composite launch tube of man portable air defense system

Purpose The purpose of this paper is to find the optimum configuration of the composite launch tube currently being developed in Roketsan. The winding thicknesses and winding angles of the launch tube are selected as design variables, and three different composite material alternatives are evaluated: glass/epoxy, carbon/epoxy and aramid/epoxy. Design/methodology/approach In this study, structural optimization of a composite launch tube of man portable air defense system is conducted. To achieve a cost-effective design, a cost scoring table that includes structural weight, material cost, availability and manufacturability is first introduced. Then, optimization for minimum weight is conducted, where the winding thicknesses and winding angle are taken as design variables, and the safety factor value obtained by using the Tsai–Wu damage criterion is used as constraint. A surrogate-based optimization approach is used where various options for surrogate models are evaluated. Glass/epoxy, carbon/epoxy and aramid/epoxy are considered as alternative materials for the launch tube. Finally, the selection of the most cost-effective design is performed to achieve optimum cost. Findings Carbon fiber-reinforced epoxy matrix material provides the optimum cost-effective design for the launch tube. Practical implications The findings of the paper can be used to design more cost-efficient composite launch tube currently being developed in Roketsan. Originality/value The existing studies are based on a design approach to achieve minimum weight of the launch tubes, whereas this study introduces a design approach to achieve optimum cost.

Dimensional chains for ensuring that the assembled axisymmetric housing is inserted into the guide hole

Dimension chains were calculated using the example of a jet engine housing entering the launch tube. It was found that the method used does not take into account the actual values of losses and requires signifi cant reliability in the radical runout of the collected rocket engine case. A method for controlling radial runout in prisms is also considered.

Numerical Simulation of the Added Mass and Drag of a Uniform and Accelerated Motion Projectile

The added mass, drag and drag coefficient of a uniform and accelerated motion projectile in viscous incompressible fluid were calculated by numerical simulation and dynamic mesh method. The effect of velocity and acceleration on the added mass, drag and drag coefficient of the projectile in a launch tube was investigated. The results show that the variation rules of added mass, drag and drag coefficient are basically the same when the projectile moves at different speeds. The added mass, drag and drag coefficient become smaller and drag becomes bigger with the increase of speed. The variation rules of the added mass, drag and drag coefficient are the same as uniform motion when the projectile moves at different accelerations. The added mass and drag coefficient become smaller and drag becomes bigger with the increase of acceleration. These reveal that the motion region, velocity and acceleration have some effect on the added mass, drag and drag coefficient.

Application of the Projection Pursuit Regression in Forecasting the Pressure of the Torpedo Launch Tube

Through the relation among the pressure of the torpedo launch tube, cylinder volume, cylinder pressure and emission valve size, we adopt the projection pursuit regression method and establish the model to predict the pressure of the torpedo launch tube. Through the comparison of experiment data and model prediction, fitting accuracy of this relation model is higher than that of the partial least-squares regression method and linear regression model and the projection pursuit regression is an efficient method which can research the initial ballistic trajectory of ship launched torpedoes.

Heat Transfer Enhancement of Launch Tube Using Free Convection: Parametric Design and Investigation

To alleviate the damages on launch tube surface from high temperature the rocket exhaust gas during firing the missile, we thus propose the heat transfer enhancement mechanism for the tube wrapped with metal sheet providing the small space, so-called air gap. The idea of the augmentation is by creating the free convection flow pattern in the narrow gap making by wrapping the metal sheet around the launch tube. In this present work, design of experiment is applied to parametrically design the launch tube with metal cover sheet configuration (cylindrical annulus with fins). The objective is to parametrically design and investigate the configuration of the metal-sheet-wrapped launcher. To predict the free convection in narrow cylindrical annulus heated from the below surface (launch tube) including the rotating effect, the CFD investigation of the time-variant axissymmetric flow is conducted. The influences of three design factors, diameter and position of exit channels and air gap thickness on the flow field and the heat transfer are investigated.