Browse Topic: Thrust
The experimental investigation analyzed the performance of three machining conditions: dry machining, cryogenic machining, and cryogenic machining with minimum quantity lubrication (MQL) on tool wear, cutting forces, material removal rate, and microhardness. The outcome of this study presents valuable knowledge regarding optimizing conditions of turning operations for Ti6Al4V and understanding the machinability under cryogenic-based cooling strategies. Based on the experimentation, cryogenic machining with MQL is the most beneficial approach, as it reduces cutting force and flank wear with a required material removal rate. This strategy significantly enhances the machining efficiency and quality of Ti6Al4V under variable feed rates (0.05 mm/rev, 0.1 mm/rev, 0.15 mm/rev, 0.2 mm/rev, 0.25 mm/rev) where cutting velocity (120 m/min) and depth of cut (1 mm) are constant. The effects of the main cutting force, feed force, thrust force, material removal mechanism, flank wear, and
NWI Aerostructures Park City, KS
In any human space flight program, safety of the crew is of utmost priority. In case of exigency in atmospheric flight, the crew is safely and quickly rescued from the launch vehicle using Crew Escape System (CES). CES is a critical part of the Human Space Flight which carries the crew module away from the ascending launch vehicle by firing its rocket motors (Pitch Motor (PM), Low altitude Escape Motor (LEM) and High altitude Escape Motor (HEM)). The structural loads experienced by the CES during the mission abort are severe as the propulsive, aerodynamic and inertial forces on the vehicle are significantly high. Since the mission abort can occur at anytime during the ascent phase of the launch vehicle, trajectory profiles are generated for abort at every one second interval of ascent flight period considering several combinations of dispersions on various propulsive parameters of abort motors and aero parameters. Depending on the time of abort, the ignition delay of PM, LEM and HEM
Thrust measurement systems come in many sizes and shapes, with varying degrees of complexity, accuracy and cost . For the purposes of this information report, the discussions of thrust measurement will be limited to axial thrust in single-axis test systems.
In an application first, the physics of why the sky is blue is used to measure gas flows without obstructive sensors. A longstanding industry partnership between Virginia Polytechnic Institute and State University (Virginia Tech) and Pratt & Whitney has resulted in a new laser-optical technology that aims to revolutionize in-flight thrust measurement.
This document defines and illustrates the process for determination of uncertainty of turbofan and turbojet engine in-flight thrust and other measured in-flight performance parameters. The reasons for requiring this information, as specified in the E-33 Charter, are: determination of high confidence aircraft drag; problem rectification if performance is low; interpolation of measured thrust and aircraft drag over a range of flight conditions by validation and development of high confidence analytical methods; establishment of a baseline for future engine modifications. This document describes systematic and random measurement uncertainties and methods for propagating the uncertainties to the more complicated parameter, in-flight thrust. Methods for combining the uncertainties to obtain given confidence levels are also addressed. Although the primary focus of the document is in-flight thrust, the statistical methods described are applicable to any measurement process. The E-33 Committee
The reactionless drive is an internal momentum engine which until recently has been deemed impossible under the laws of physics. In this paper, the authors will extend the equation for reaction less propulsion = F=−μq2/6πcmr2v×dBdt+B×dvdt and derive an additional equation, which we call “The Sektet Equation” governing the system of motion, FSek=−μq2/6πcmr2∗2B∗dBdt. The results of the paper show that significant thrusts can be generated on relatively low voltages and energy inputs. It applies this equation to explain how NASA’s EM drive likely produces thrust via the “Sektet Equation” using a three circuit analysis of the Sektet Force.
This method covers electric outboards that are rated in terms of static thrust.
In-space and planetary surface assembly for human exploration is a challenging domain that encompasses various technological thrusts to support human missions. NASA is developing autonomous assembly agents to build structures like habitats and antennae on the Moon. These modular and reconfigurable Assembler robots will provide robotic assembly of structures, even in locations that prohibit constant human oversight and teleoperation.
Researchers at NASA’s Jet Propulsion Laboratory (JPL) are developing a novel microthruster that could provide easy-to-control propulsion during spaceflight. Using solid silver as the fuel source, this innovative microthruster provides thrust via electrospray without heating the fuel reservoir or transporting liquid metals. Instead of transporting a molten metal, this design transports metal ions via a solid electrolyte film.
IVO Ltd. Bismark, ND +1 701-390-9567
Slowed rotors – traditionally associated with autogyros and gyroplanes – have long been recognized as one potential solution for high-speed helicopters (200-300 knots). During the 1950s–70s, there were several significant programs that led to the development of high-speed helicopters with thrust and lift compounding. The key technology barriers common to all were extremely high fuel consumption due to high advancing side drag and large reverse flow, complexities associated with RPM reduction, large blade motions during RPM reduction, and unexplained but catastrophic aeroelastic instabilities of rigid rotors (Cheyenne). None of these helicopters entered regular production.
This paper describes the implementation, integration, testing and performance evaluation of compact and battery-less alternator with external regulator for diesel engine for avionics application. The key responsibility of this alternator is to generate 2.8kW power with 28V regulated power supply for various loads. The alternator has been integrated and installed on the diesel engine and further tested on dynamometer and thrust cradle with propeller combination. The alternator when used in conjunction with ACU (Alternator Control Unit) that is designed to boot strap field voltage during low speed operation, has the ability to self-excite. The alternator / ACU system has the ability to generate power even in the absence of battery voltage i.e. in battery less systems or those in which the battery is not always connected to the alternator. External voltage regulator has been used which minimizes ripple up to 1.0V. The alternator rpm ranges from 3000 to 10000 for generating maximum power
Passengers would always like to reach their destinations with minimum commute time. Generating a higher thrust is a necessity. This implies that the turbomachinery associated with the power plant has to rotate faster and with higher efficiencies. However, high rotational speeds, mainly in the transonic regime, often lead to boundary layer separation, shocks, compressor stall, and surge. The current investigation is an attempt to reduce the abovementioned phenomena. It involves the performance study of a smoothened controlled diffusion airfoil (CDA) blade that has been optimized by “Multi-Objective Genetic Algorithm” (MOGA) by altering maximum camber location and stagger angle. Inlet pressure is varied from 15 kPa to 30 kPa and the angle of attack ranging from 40.4° to 56.4°. C48-S16-BS1 is validated and considered as the baseline profile, and all other blades are collated to this. It is observed that shifting the location of the maximum camber close to the leading edge and increasing
Reduction gears are very commonly used in the automotive and aviation industries. A propeller’s efficiency decreases rapidly as the speed of the blade tips nears the speed of sound. An engine reduction gear enables the engine to develop more torque while reducing the propeller’s revolutions per minute (RPM). This prevents the propeller’s efficiency from decreasing. This work deals with a detailed methodology for the design and analysis of a single-stage reduction gear. Custom pinion and wheel were modelled along with the engine assembly. A custom mount was designed and fabricated to allow for engine-reduction gear system integration. In this work, a 7.5 cubic centimeter (cc) single-cylinder glow engine is used. Bending and contact stress analysis was performed, and the results were compared with the calculated stress values. The torque demands were analyzed for propellers of different sizes at varying aircraft speeds. Quantitative analysis of thrust is also carried out before and after
A 3D CFD methodology is presented to simulate ice build-up on propeller blades exposed to known icing conditions in flight, with automatic blade pitch variation at constant RPM to maintain the desired thrust. One blade of a six-blade propeller and a 70-passenger twin-engine turboprop are analyzed as stand-alone components in a multi-shot quasi-steady icing simulation. The thrust that must be generated by the propellers is obtained from the drag computed on the aircraft. The flight conditions are typical for a 70-passenger twin-engine turboprop in a holding pattern in Appendix C icing conditions: 190 kts at an altitude of 6,000 ft. The rotation rate remains constant at 850 rpm, a typical operating condition for this flight envelope. Two icing conditions are simulated: air static temperature -23 °C, LWC 0.2 g/m3 and MVD 20 microns resulting in rime ice, and air static temperature -16 °C, LWC 0.3 g/m3 and MVD 20 microns resulting in mixed ice with rime to glaze transition in the radial
This standard establishes the basic triangular profile for the MJB thread form, the design profiles, standard pitches, tolerance classes, formulae for tolerances and dimensions, tolerance tables, and a system of designations. Because of the specialized application for buttress threads, no preferred diameter-pitch series have been established for this standard and each application will require use of the thread formulae for dimensions and related tolerances given herein for deriving the thread dimensional requirements.
This SAE Aerospace Information Report (AIR) records the results of an investigation of a dual rotation propeller shaft standard for an engine supplied bearing and the reason for deciding that such a bearing is impracticable.
A highly miniaturized, MR-143, green monopropellant thruster was developed for 1N thrust. Testing indicated the initial catalyst bed heater was insufficient. In subsequent development, the thruster was equipped with a more efficient catalyst bed heater. For reliable ignition of the advanced, non-toxic, AF-M315E monopropellant, the catalyst needs to be preheated. This preheat temperature is much higher than what hydrazine thrusters require. Moreover, the combustion temperature of hydroxyl ammonium nitrate (HAN)-based monopropellants is higher than hydrazine, so the catalyst bed heater must be able to withstand repeated soak-back temperatures.
In this study, we focus on “camber angle control” and “derivative steering assistance” using “steer-by-wire” as maneuverability and stability improvement techniques that are appropriate for the electric vehicle (EV) era. Movements that produce a negative camber angle generate camber thrust, and vehicle motion performance improvements extend from the fact that the tire side force is increased by the camber thrust effect. In our experimental vehicle, a proportional steering angle system was used to create negative camber angle control via an electromagnetic actuator that allowed us to confirm improvements to both the effectiveness and stability of steering control in restricted cornering areas. More specifically, we determined that it is possible to improve critical cornering performance by executing ground negative camber angle control in proportion to the steering angle. Steer-by-wire refers to an electrical steering technique that allows the steering angle of the entire vehicle to be
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