In reality all the engineering products are likely to deviate from their expected performance due to the presence of variations. The variations can cause any product optimization to easily fall into sub-optimal regime. In present adopted methodology, the robust design optimization (RDO) of the objective function makes performance insensitive to the variations/uncertainties. A hybrid optimizatio...

Aerodynamic design optimization of an airfoil for the Mars exploration airplane has been demonstrated by using an evolutionary algorithm. The adaptive range genetic algorithm is used for efficient and robust design optimization. Two-dimensional Navier-Stokes solver is used for accurate aerodynamic performance evaluation. The present computation is parallelized on the SX-6 vector computers in In...

Introduction Switched reluctance motors (SRMs) have several advantages (rotor simplicity, high speed operation, ease of repairing, high degree of independence between phases, short end-turn, and low inertia) and used for aerospace systems, marine propulsion systems, linear drives, mining drives, hand held tools and home utility applications. However, a major disadvantage of SRM is vibration pro...

A scheme for identifying and visualizing the material properties that limit the performance of candidate materials for actively cooled aerospace propulsion components is presented and illustrated for combustor panels for Mach 7 hypersonic vehicles. The method provides a framework for exploring the nonlinear interactions between design and materials optimization. By probing the active constraint...

In this paper, the three-component power decomposition for polarimetric SAR (PolSAR) data with an adaptive volume scattering model is proposed. The volume scattering model is assumed to be reflection-symmetric but parameterized. For each image pixel, the decomposition first starts with determining the adaptive parameter based on matrix similarity metric. Then, a respective scattering power comp...

a new approach for propulsion system layout that increases power and enhances the efficiency of submarine propulsion system is proposed.using our method,the efficiency and power of the system enhances without increasing volume and weight. this layout improves the performance compared to the usual layout, which employs double-armature motors in cruise speed where efficiency is more critical. thi...

Current interest in advanced propulsion within NASA and research activities in advanced propulsion concepts at the Jet Propulsion Laboratory are reviewed. The concepts,which include high power plasma thrusters such as lithiun~-fueled Lorentz-Force-Accelerators,MEMS-scale propulsion systems, in-situ propellant utilization techniques, fusion propulsion systems and methods of using antimatter, off...

Cryogenic cavitation affects the operation of liquid propulsion systems during first phase a launch. Its effects within orifices or turbopumps can range from mild instabilities to catastrophic damages structures, jeopardizing launch itself. Therefore, ensure proper designing systems, phenomena cannot be neglected. Although hydrodynamic has been studied for decades, impact nature fluid sparsely ...

Objectives: Wheelchairs are the prime mobility aid of persons with spinal cord injuries. Manual wheelchair propulsion puts a lot of demand on the cardiopulmonary as well as the skeletal system. The main purpose of the study was to compare the effects of both arm ergometry training and progressive resistance exercise training of upper limbs on resting heart rate and distance covered during wheel...