Range (aeronautics)

About: Range (aeronautics) is a research topic. Over the lifetime, 7268 publications have been published within this topic receiving 67495 citations. The topic is also known as: autonomy.

Endothermic fuels for hypersonic vehicles

Abstract: The use of hydrocarbon fuels for hypersonic vehicles will require increasing utilization of the fuel as vehicle speed increases. In order to achieve maximum heat sinks endothermic reactions must be employed to augment fuel enthalpy. Various reactions, such as thermal cracking, depolymerization, dehydrogenation, and dehydrocyclization, can be used and have been studied. Of these, the catalytic dehydrogenation of naphthenes shows the most promise for practical application. The dehydrogenation of MCH over a Pt/AJfoOa catalyst can approximately double the 1000 Btu/lb available from fuel enthalpy. This should provide cooling sufficient to allow flight into the range of Mach 10 at optimum altitude. However, the application of cooling to the various portions of the aircraft will present formidable problems. Factors that are important in this consideration such as thermal stability, reaction rate, reactor weight and volume, heat transfer, pressure drop, combustion characteristics, and the mating of the cooling system to the aircraft are discussed.

Energy Approach to the General Aircraft Performance Problem

Abstract: The general aircraft performance problem is considered from the point of view of the balance that must exist between the potential and kinetic energy change of the aircraft, the energy dissipated against the drag, and the energy derived from the fuel. This approach yields as one result a basic equation for the rate of change of the sum of the potential and kinetic energies of an aircraft. The form of the equation points to the use of aircraft total energy rather than altitude as the significant independent variable in the climb performance of high-speed aircraft. Using this equation, a method is outlined which permits finding either the path of minimum time or minimum fuel to change from one combination of speed and altitude to another. The energy balance approach yields as another result a form of the aircraft range equation which incorporates a correction for the total energy change during the cruising portion of the flight. This form of the range equation shows that the dimension and the order of magnitude of aircraft range are given by the heat content of the fuel. Finally, the parameters of the range equation are examined to obtain an indication of the range capabilities of aircraft at supersonic speeds relative to those at subsonic speeds.

Effect of Platooning on Fuel Consumption of Class 8 Vehicles Over a Range of Speeds, Following Distances, and Mass

Abstract: This research project evaluates fuel consumption results of two Class 8 tractor-trailer combinations platooned together compared to their standalone fuel consumption. A series of ten modified SAE Type II J1321 fuel consumption track tests were performed to document fuel consumption of two platooned vehicles and a control vehicle at varying steady-state speeds, following distances, and gross vehicle weights (GVWs). The steady-state speeds ranged from 55 mph to 70 mph, the following distances ranged from a 20-ft following distance to a 75-ft following distance, and the GVWs were 65K lbs and 80K lbs. All tractors involved had U.S. Environmental Protection Agency (EPA) SmartWay-compliant aerodynamics packages installed, and the trailers were equipped with side skirts. Effects of vehicle speed, following distance, and GVW on fuel consumption were observed and analyzed. The platooning demonstration system used in this study consisted of radar systems, Dedicated Short-Range Communication (DSRC) vehicle-to-vehicle (V2V) communications, vehicle braking and torque control interface, cameras and driver displays. The lead tractor consistently demonstrated an improvement in average fuel consumption reduction as following distance decreased, with results showing 2.7% to 5.3% fuel savings at a GVW of 65k. The trailing vehicle achieved fuel consumption savings ranging from 2.8% to 9.7%; tests during more » which the engine cooling fan did not operate achieved savings of 8.4% to 9.7%. 'Team' fuel savings, considering the platooned vehicles as one, ranged from 3.7% to 6.4%, with the best combined result being for 55 mph, 30-ft following distance, and 65k GVW. « less

Vehicle data services

Abstract: A method and devices are described for wirelessly uploading and downloading data to and from a mobile vehicular platform while within range of a coordinated network of base stations that monitor the location of the vehicle and optimize data throughput using any combination of diversity and beam forming adaptive antenna techniques while the vehicle is on the ground or additionally in the case of aircraft, not only on the ground, but also during take-off, climb, en-route, holding, on-approach, touchdown and rollout. Particularly, in describing this art, the intent is to address the aspects of a quantifiable vehicle environment, where the vehicle's behavior is predictable, such as in train routes, bus routes, ship dockings and aircraft flight plans.

Hover, Transition, and Level Flight Control Design for a Single-Propeller Indoor Airplane

Abstract: This paper presents vehicle models and test flight results for an autonomous fixed-wing aircraft with the capability to take off, hover, transition to and from level-flight, and perch on a vertical landing platform. These maneuvers are all demonstrated in the highly space constrained environment of the Real-time indoor Autonomous Vehicle test ENvironment (RAVEN) at MIT. RAVEN promotes the rapid prototyping of UAV planning and control technologies by allowing the use of unmodified commercially available model aircraft for autonomous flight. Experimental results of several hover tests, transition maneuvers, and perch landings are presented. By enabling a fixed-wing UAV to achieve these feats, we demonstrate that the desirable speed and range performance of an autonomous fixed-wing aircraft in level flight can be complimented by hover capabilities that are typically limited to rotary-wing vehicles. This combination has the potential to significantly ease support and maintenance of operational autonomous vehicles.