Propulsion

About: Propulsion is a research topic. Over the lifetime, 24977 publications have been published within this topic receiving 200311 citations.

Bringing an Effective Solar Sail Design Toward TRL 6

Abstract: Solar sails reflect photons streaming from the sun and convert some of the energy into thrust. This thrust, though small, is continuous and acts for the life of the mission without the need for propellant ( I ) . Recent advances in sail materials and ultra-low mass structures have enabled a host of useful missions utilizing solar sail propulsion. The team of L Garde, Jet Propulsion Laboratories, Ball Aerospace, and Langley Research Center, under the direction of NASA, has been developing a solar sail configuration to address NASA s future space propulsion needs. Utilizing inflatably deployed and Sub Tg rigidized boom components, this 10,000 sq m sailcraft achieves an areal density of 14.1 g/sq m and a characteristic acceleration of 0.58 mm/s . The entire configuration released by the upper stage has a mass of 232.9 kg and requires just 1.7 d of volume in the booster. After deployment, 92.2 kg of non-flight required equipment is jettisoned resulting in a sailcraft mass, including payload and control system, of 140.7 kg. This document outlines the accomplishments of a Phase 1 effort to advance the technology readiness level (TRL) of the concept from 3 toward a TRL of 6. The Phase 1 effort, the first of three proposed phases, addressed the design of the solar sail, its application to several missions currently under review at NASA, and developed a ground tes plan to bring the technology toward a TRL of 6.

Overview of the USAF Electric Propulsion Program

Abstract: : An overview of current electric propulsion research and development efforts within the United States Air Force is presented. The Air Force supports electric propulsion primarily through the Air Force Office of Scientific Research (AFOSR), the Air Force Research Laboratory (AFRL) and the AFOSR European Office of Aerospace Research and Development (EOARD). Overall direction for the programs comes from Air Force Space Command (AFSPC), with AFRL mission analysis used to define specific technological advances needed to meet AFSPC priorities. AFOSR funds basic research in electric propulsion throughout the country in both academia and industry. The AFRL Propulsion Directorate conducts electric propulsion efforts in basic research, engineering development, and space flight experiments. EOARD supports research at foreign laboratories that feeds directly into AFSR and AFRL research programs. Current research efforts fall into 3 main categories defined loosely by the thruster power level. All three agencies are conducting research at the low-power regime (P 30 kW) is realizing increased emphasis.

Fuzzy-Sliding Mode Speed Control for Two Wheels Electric Vehicle Drive

Abstract: Electric vehicles (EV) are developing fast during this decade due to drastic issues on the protection of environment and the shortage of energy sources, so new technologies allow the development of electric vehicles (EV) by means of electric motors associated with static converters. The proposed propulsion system consists of two induction motors (IM) that ensure the drive of the two back driving wheels. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling, independently, every driving wheel to turn at different speeds in any curve. This paper presents the study of an hybrid Fuzzy-sliding mode control (SMC) strategy for the electric vehicle driving wheels, stability improvement, in which the fuzzy logic system replace the discontinuous control action of the classical SMC law .Our electric vehicle fuzzy-sliding mode control’s simulated in Matlab SIMULINK environment, the results obtained present the efficiency of the proposed control with no overshoot, the rising time is perfected with good disturbances rejections comparing with the classical control law.