Propulsion

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

Underwater Bioinspired Propulsion: From Inspection to Manipulation

Abstract: This article presents the design of a biomimetic underwater vehicle-manipulator system (BUVMS) with bioinspired long-fin propulsion and its control methods. The kinematic analysis of bioinspired long-fin propulsion is conducted, and the maximum thrust of this propulsion derived from our thrust measurement platform can be up to 25 N. Bioinspired long-fin propulsion is introduced to construct the BUVMS for inspection and manipulation tasks, and the system architecture of the BUVMS is described. Moreover, real-time dynamic dubins-helix path planning and tracking of the biomimetic vehicle are proposed to realize the arrival of the desired pose. The tracking error is less than 0.23 body length. Finally, coordinated control between the biomimetic vehicle and the manipulator is developed to achieve autonomous manipulation. The reaction of the manipulator served as feedforward compensation is added into the closed-loop control of the biomimetic vehicle. The experimental results are provided to illustrate the validity of the proposed methods.

Gearing ratios of a magnetic gear for marine applications

Abstract: Marine propulsion systems have become increasingly electromechanical in recent years. Proposed systems show increasing torque density in an effort to reduce volume and weight. A magnetic gear is proposed to reduce the size of the propulsion motor and achieve similar torque amplification provided by a mechanical gearbox, without the maintenance and breakdown issues. A magnetic gearbox, of the concentric planetary type, will be studied for the high-torque low-speed requirements of a marine propulsion system. Torque ripple is investigated across multiple models to determine acceptable torque transfer performance.

Basic principle and design criteria of axial-flux PM machines having counter-rotating rotors

Abstract: Axial-flux PM machines are particularly suitable for application in electrical drives devoted to ship propulsion, since they allow the elimination of the large-power gearbox used in conventional systems. In consideration of that, this paper deals with a novel slotless axial-flux PM machine topology which is characterized by the synchronous counterrotation of the two machine rotors. Such a new machine topology can find application in the direct driving of two counterrotating propellers, which may be used in ship propulsion systems to recover energy from the rotational flow of the main propeller slip stream. In this case, the use of an axial-flux machine having counter-rotating rotors allows an improvement in terms of weight and efficiency, since the epicyclic gear otherwise required for the motion reversal can be avoided. The paper discusses the stator winding arrangement which allows the opposite motion of the machine rotors and reports experimental results taken from a small-size machine prototype. >

Boat propulsion system

Abstract: The invention relates to a boat propulsion system comprising at least one propeller (8), at least one electric motor (7) by means of which the at least one propeller can be driven, and one converter-fed power supply unit. The at least one electric motor (7) can be supplied with electric power by means of said power supply unit which comprises at least one prime mover and at least one generator powered by said prime mover. The at least one electric motor and the at least one generator of the power supply unit are embodied as three-phase synchronous machines. In order to reduce the volume and weight of such a boat propulsion system while increasing its effectiveness, the at least one electric motor (7) that is configured as a three-phase synchronous machine and the at least one generator that is configured as a three-phase synchronous machine of the power supply unit have rotating excitation coil (10) made of high-temperature super conductor wire and each rotating excitation coil (10) made of high-temperature super conductor wire is arranged in a vacuum-tight, insulated cryostat (14) by means of which the rotating excitation coil (10) made of high-temperature super conductor wire can be chilled to a temperature of 15 to 77 K.

Development and application of high-temperature sensors and electronics for propulsion applications

Abstract: High temperature sensors and electronics are necessary for a number of aerospace propulsion applications. The Sensors and Electronics Branch at NASA Glenn Research Center (NASA GRC) has been involved in the design, fabrication, and application of a range of sensors and electronics that have use in high temperature, harsh environment propulsion environments. The emphasis is on developing advanced capabilities for measurement and control of aeropropulsion systems as well as monitoring the safety of those systems using Micro/Nano technologies. Specific areas of work include SiC based electronic devices and sensors; thin film thermocouples, strain gauges, and heat flux gauges; chemical sensors; as well as integrated and multifunctional sensor systems. Each sensor type has its own technical challenges related to integration and reliability in a given application. These activities have a common goal of improving the awareness of the state of the propulsion system and moving towards the realization of intelligent engines. This paper will give an overview of the broad range of sensor-related development activities on-going in the NASA GRC Sensors and Electronics Branch as well as their current and potential use in propulsion systems.