Part of a Book
Refine
Year of publication
Document Type
- Part of a Book (26) (remove)
Language
- English (26) (remove)
Keywords
- Wind Tunnel (3)
- Flight Test (2)
- Pitching Moment (2)
- Wave Drag (2)
- Aerodynamic Drag (1)
- Carsharing (1)
- Certification Rule (1)
- Drag Reduction (1)
- Electrical vehicle (1)
- Engine Efficiency (1)
- Evacuation Rule (1)
- Friction Drag (1)
- Ice melting probe (1)
- Ice penetration (1)
- Icy moons (1)
- Leading Edge Vortex (1)
- Mach Number (1)
- Mars (1)
- Multidisciplinary Design Optimization (1)
- Noise Exposure (1)
- Ocean worlds (1)
- Parabolized Stability Equation (1)
- Passenger compartment (1)
- Severe Accident (1)
- Sonic Boom (1)
- Specific Fuel Consumption (1)
- Supersonic Flow (1)
- Supersonic Wind Tunnel (1)
- Technology Challenge (1)
- Thermal Fatigue Testing (1)
- Thermal comfort (1)
- Thermal management (1)
- Variable Geometry (1)
- attitude dynamics (1)
- orbit control (1)
- orbital dynamics (1)
- sailcraft (1)
- solar sail (1)
Institute
- Fachbereich Luft- und Raumfahrttechnik (26) (remove)
Solar sails are large and lightweight reflective structures that are propelled by solar radiation pressure. This chapter covers their orbital and attitude dynamics and control. First, the advantages and limitations of solar sails are discussed and their history and development status is outlined. Because the dynamics of solar sails is governed by the (thermo-)optical properties of the sail film, the basic solar radiation pressure force models have to be described and compared before parameters to measure solar sail performance can be defined. The next part covers the orbital dynamics of solar sails for heliocentric motion, planetocentric motion, and motion at Lagrangian equilibrium points. Afterwards, some advanced solar radiation pressure force models are described, which allow to quantify the thrust force on solar sails of arbitrary shape, the effects of temperature, of light incidence angle, of surface roughness, and the effects of optical degradation of the sail film in the space environment. The orbital motion of a solar sail is strongly coupled to its rotational motion, so that the attitude control of these soft and flexible structures is very challenging, especially for planetocentric orbits that require fast attitude maneuvers. Finally, some potential attitude control methods are sketched and selection criteria are given.
Thermal management in E-carsharing vehicles - preconditioning concepts of passenger compartments
(2015)
The issue of thermal management in electric vehicles includes the topics of drivetrain cooling and heating, interior temperature, vehicle body conditioning and safety. In addition to the need to ensure optimal thermal operating conditions of the drivetrain components (drive motor, battery and electrical components), thermal comfort must be provided for the passengers. Thermal comfort is defined as the feeling which expresses the satisfaction of the passengers with the ambient conditions in the compartment. The influencing factors on thermal comfort are the temperature and humidity as well as the speed of the indoor air and the clothing and the activity of the passengers, in addition to the thermal radiation and the temperatures of the interior surfaces. The generation and the maintenance of free visibility (ice- and moisture-free windows) count just as important as on-demand heating and cooling of the entire vehicle. A Carsharing climate concept of the innovative ec2go vehicle stipulates and allows for only seating areas used by passengers to be thermally conditioned in a close-to-body manner. To enable this, a particular feature has been added to the preconditioning of the Carsharing electric vehicle during the electric charging phase at the parking station.
We present a new approach to the problem of optimal control of solar sails for low-thrust trajectory optimization. The objective was to find the required control torque magnitudes in order to steer a solar sail in interplanetary space. A new steering strategy, controlling the solar sail with generic torques applied about the spacecraft body axes, is integrated into the existing low-thrust trajectory optimization software InTrance. This software combines artificial neural networks and evolutionary algorithms to find steering strategies close to the global optimum without an initial guess. Furthermore, we implement a three rotational degree-of-freedom rigid-body attitude dynamics model to represent the solar sail in space. Two interplanetary transfers to Mars and Neptune are chosen to represent typical future solar sail mission scenarios. The results found with the new steering strategy are compared to the existing reference trajectories without attitude dynamics. The resulting control torques required to accomplish the missions are investigated, as they pose the primary requirements to a real on-board attitude control system.