Browse Topic: Thrust

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Impact of Toe and Thrust Angle Misalignment on Roll Behaviour of a Heavy Commercial Road Vehicle2024-26-005601/16/2024
Heavy Commercial Road Vehicles (HCRVs) may be more susceptible to rollover incidents due to their higher centre of gravity position than passenger vehicles, and rollover is one of the significant causes of HCRV accidents. Therefore, variation in vehicle roll behaviour becomes crucial to the safety of an HCRV. Toe misalignment is a commonly observed phenomenon in HCRVs, and studying its impact on roll behaviour is important. In this work, the impact of the symmetric toe and thrust misalignment on the roll behaviour of an HCRV is analysed using IPG TruckMaker®, a vehicle dynamics simulation software. A ramp steer manoeuvre was used for the simulations, and the toe misalignment on a wheel was chosen from the range [−0.21°, 0.21°]. Variation in roll behaviour was quantified using the steering wheel angle at which one-wheel lift-off (OWL) occurred (SWA_L). Additionally, an analytical model was formulated to predict OWL and the model predictions were compared with the results from IPG
Chandran, Amarchand, Grandhe, Roshan, Mukhopadhyay, Arko, Sharma, Mitanshu, Shankar Ram, C S
Three-axle Bus Handling Dynamics Evaluation Index2022-01-034103/29/2022
This paper evaluates the handling characteristics of three-axle bus by using the unique comprehensive vehicle handling evaluation index. With the theory of total variance, the generalized side-slip angle unified transfer function is introduced to derivate the evaluation indexes of reaction time, transition time, damping ratio and total variance considering the suspension roll steer and camber thrust. The three-axle bus suspension roll steer and camber thrust produces extra lateral force. The three-axle vehicle response degree following the step steer input is analyzed with the effect of suspension roll on three-axle bus by using the total variance approach. The vehicle designers could use this approach to get optimization design parameters of bus suspension. The unique total variance evaluation index considering the suspension roll steer is useful and could serve as an important tool for evaluating the effect of suspension roll on three-axle bus handling dynamics.
Ding, Jinquan
Multirotor Aircraft Noise ReductionTBMG-3820112/01/2020
Noise produced by multirotor vehicles may be objectionable to some, especially as industry moves toward drone deliveries and potentially air taxi operations. Multirotor aircraft typically create a significant amount of tonal noise from each rotor. Groups of rotors operating at the same rotation rate with an appropriate phase offset can be used to reduce the tonal noise of the aircraft when there are multiple rotors on each side of the aircraft. Reducing tonal noise, depending on the aircraft design, can effectively reduce the total noise output for a given flight scenario.
Bio-Inspired PropulsionTBMG-3721907/01/2020
From the vibrations of the rear-view mirror just as a car reaches 70 miles per hour to a building that collapses when, in an earthquake, it begins to vibrate at a specific frequency, there is untapped energy that could be harnessed for propulsion. Researchers found relationships between frequencies and the passive dynamics at play when vehicles move in air or water that help them understand how to use these forces to enhance performance.
EDITORIAL: Impressions of a rocket launch20AUTP06_0506/01/2020
For a brief but illuminating moment, advanced engineering at its finest was on the world stage. The May 30, 2020, launch from Cape Canaveral of two American astronauts, destined for the orbiting International Space Station (ISS), marked the first time since 2011 that the U.S. put humans into space from home soil. The reawakening of the U.S. space program is invigorating to those who understand the value of technical achievement on a grand scale-and who simply love seeing giant rockets blast off into the sky. And its joint public-private partnership of NASA and SpaceX is historic. The iconic government agency provided funding, its hallmark safety oversight and crew for the recent Demo-2 spaceflight. SpaceX, founded in 2002 by a pre-Tesla Elon Musk, supplied the mission's Crew Dragon capsule and reusable Falcon-9 rocket.
Brooke, Lindsay
Numerical Simulation of Aircraft and Variable-Pitch Propeller Icing with Explicit Coupling2019-01-195406/10/2019
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
Ozcer, Isik, Baruzzi, Guido S., Desai, Miraj, Yassin, Maged
Potential Improvements in Turbofan’s Performance by Electric Power Transfer2018-01-196210/30/2018
Bleeding in engines is essential to mitigate the unmatched air massflow between low and High Pressure (HP) compressors at low speed settings, thus avoiding unstable operation due to surge and phenomena. However, by emerging the More Electric Aircraft (MEA) the engine is equipped with electrical machines on both high and Low Pressure (LP) spools which enables transfer of power electrically from one spool to another and hence provides the opportunity to operate engine core components closer to their optimum design point at off-design conditions. At lower power setting of the engine, HPC speed can be increased by taking power from LP shaft and feeding it to HP shaft which can lead to the removal of the bleeding system which in turn reduces weight and fuel consumption and help to overcome engine instability issues. Fuel consumption can be decreased by decreasing inconsistent thrust with the aircraft mission for flight and ground idle settings. This paper investigates the idea of power
Balaghi Enalou, Hossein, Le-Peuvedic, Jean-Marc, Rashed, Mohamed, Bozhko, Serhiy
Thruster-Based Attitude and Translation Control with Minimum Pulse-Count Disturbance RejectionTBMG-2873704/01/2018
Thruster-based control typically requires a substantial engineering effort in order to mitigate an important issue: the control system tends to use many thruster pulses to accomplish what a single thruster pulse could do instead. This fundamental problem arises because the standard controller’s feedback response is (by definition) proportional to the spacecraft’s current tracking error state alone, without regard for the time-integrated tracking error. By ignoring this particular signal, it becomes especially difficult to build a control system that realizes the following performance capabilities (PCs):
Effect of the Structure of Radial Vane Cavity on Performance of Turbine Inter-Vane Burner Based on Jet-Vortex Flow2017-01-228410/08/2017
The potential benefits of reheat burner placed between turbine stages for propulsion system have been recognized for nearly a century. Compared to the conventional non-reheat engines, the turbine inter-guide-vane burner (TIB) engines by using jet-swirl flow scheme (high-G loading) are shown to have a higher specific thrust with no or only small increase in thrust specific fuel consumption. But, it is a known fact that the G loading in the circumferential cavity is inversely proportional to the radius of the circumferential cavity. If one needs to scale this configuration for a larger spool of turbine components, the effeciency of the high G operation and obtained benefits on flame speed will reduce and hence the performance will de-grade. Hence to make a universal TIB, an alternate approach was proposed using a trapped vortex cavity to replace the jet-swirl flow combustion to enhance mixing rates via a jet-vortex flow in the cavity, followed by further mixing of the free stream air
Zheng, Haifei
Experimental Study of Dielectric Barrier Discharge Driven Duct Flow for Propulsion Applications in Unmanned Aerial Systems2017-01-206309/19/2017
The dielectric barrier discharge (DBD) has been studied significantly in the past two decades for its applications to various aerodynamic problems. The most common aerodynamic applications have been stall/separation control and boundary layer modification. Recently several researchers have proposed utilizing the DBD in various configurations to act as viable propulsion systems for micro and nano aerial vehicles. The DBD produces stable atmospheric-pressure non-thermal plasma in a thin sheet with a preferred direction of flow. The plasma flow, driven by electrohydrodynamic body forces, entrains the quiescent air around it and thus develops into a low speed jet on the order of 10-1 to 101 m/s. Several researchers have utilized DBDs in an annular geometric setup as a propulsion device. Other researchers have used them to alter rectangular duct flows and directional jet devices. This study investigates 2-D duct flows for applications in micro plasma thrusters. The DBD actuators are located
Browning, Patrick, Shambaugh, Bryan, Dygert, Joseph
Design, Development & Testing of Test Rig Setup for UAV Propulsion System2017-01-206409/19/2017
In the present market, multiple sophisticate and expensive Thrust Test Rigs for Brushless Motors (BLDC Motor) are available making it impossible to conduct such thrust analysis on a regular and cost effective basis. Moreover the present test rigs are incapable to measure high Thrust values. This needs specialized thrust testing rig which is more expensive. This paper aims at Design & Development of the Small Scale Test Rig Setup for measurement of the thrust of any Brushless DC motor and helps in refining the Selection of motor and propeller. This is a set up based on cost efficiency factor to implement such rigs, test and for comparing the static thrust produced by the BLDC motor. The fairly simple construction contains a weighing machine, a Tachometer and a Wattmeter to measure the Thrust, RPM and the Current Drawn respectively, and provide comprehensive, accurate and efficient data coming from the BLDC Motor including the Propeller and Electronic Speed Control (ESC).
M, Parvez Alam, Manoharan, Dinesh, Chandramohan, Satheesh, Chakkath, Sabarish, MAURYA, Sunil
Uncertainty of In-Flight Thrust DeterminationAIR1678B (Current)10/22/2016
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
E-33 In Flight Propulsion Measurement Committee
Commercial Vehicles Thrust Rod Static and Dynamic Characteristics Analysis2016-01-234510/17/2016
In order to study the static and dynamic characteristics of the thrust rod. Based on the multi-body dynamics theory, the dynamic model of the thrust rod and the vehicle system is established by using ADAMS software. The limit braking condition is simulated, and the limit braking load of the thrust rod is obtained. Thrust rod finite element model is established, the load calculation value and rubber test data as a finite element analysis of input conditions, using ABAQUS software to carry on the stiffness and strength analysis, analysis results show that the strength meets the requirement, and the stiffness and strength calculation result is in good agreement with the sample test, accurately describes the finite element model. The analytical method used can be used to predict the stiffness of the thrust rod. Thrust rod finite element modal analysis were carried out to obtain the thrust rod as a whole and local low order vibration mode and natural frequency, contrast the calculated
Feng, Guoyu, Shi, Wenku, Zhang, Henghai
Internal Thrust Force Analysis of CVT Push Belt2016-01-235310/17/2016
A CVT belt is composed of multiple elements and layered rings. Each of these component parts generates loss, including relative slippage caused by the geometrical relationship between the elements and innermost ring layer. An effective way of increasing CVT efficiency is to reduce this slippage. However, since the relative slippage also controls whether the rings transmit constant torque at all times, reducing the slippage will also have an effect on the torque transmission performance of the rings. Therefore, to improve CVT efficiency by reducing the relative slippage, it is first necessary to analyze the changes to torque transmission. However, this slippage is a phenomenon of the inner portion of the belt and it is extremely difficult to identify the internal thrust force when actual load is applied. This paper describes experiments carried out to analyze the changes in each torque transmission ratio when the relative slippage between the elements and innermost ring layer changes
Harima, Kazunori, Tsuchiya, Shinji, Morino, Takuro, Nagasawa, Yuji
Performance Enhancement of Subsonic Turbofans2016-01-201809/20/2016
The key commercial aircraft propulsion requirements toward ensuring flight safety, operational efficiency, reduced CO2 footprint, and community acceptability include high installed thrust, low specific fuel consumption, and reduced noise. The objective of this paper is to highlight the various ways turbofan performance can be enhanced. First the advantage of high bypass ratio (BPR) configurations will be explained with the help of clean sheet cycle designs with the corresponding off-design performance. The achievement of hot day performance and improved durability with high BPR designs, and the benefit from core supercharging has been presented. Next, the use of on-line control effector modulations, including variable bypass exhaust nozzle, for further improvement in cruise SFC (up to an indicated 2.6%) is shown. This is followed by a discussion of medium BPR mixed exhaust designs which have a performance advantage compared to the same BPR separate exhaust configurations. Additionally
Khalid, Syed J.
Closure Slam CAE Method Investigation for Automobiles2016-01-134904/05/2016
In the current scenario, the major thrust is to simulate the customer usage pattern and lab test using virtual simulation methods. Going ahead, prime importance will be to reduce the number of soft tool prototype for all tests which can be predicted in CAE. Automotive door slam test is significantly complex in terms of prediction through simulation. Current work focuses on simulating the slam event and deriving load histories at different mounting locations through dynamic analysis using LSDyna. These extracted load histories are applied to trimmed door Nastran model and modal transient analysis is performed to find the transient stress history. This approach has a significant advantage of less computation time and stress-convergence with Nastran for performing multiple design iterations compared to LSDyna. Good failure correlation is achieved with the test using this approach. Using these load histories, design improvements are evaluated and robustness of the approach is validated. An
Unadkat, Siddharth Bhupendra, Kangde, Suhas, Burkul, Mahalingesh, Badireddy, Mahesh
Six-Degree-of-Freedom Control With Only Eight ThrustersTBMG-2346212/01/2015
Typical spacecraft thruster configurations are often unable to provide full six-degree-of-freedom control and may have unwanted interaction between their attitude control and trajectory control functions, have undesirably high instantaneous electrical power demands, and use more thrusters than desirable. These last two potential problems gain increased significance if a spacecraft is required to have especially small size and mass, and have very low cost.
Self-Adjusting Cutting Parameter Technique for Drilling Multi-Stacked Material2015-01-250209/15/2015
This study investigates the self-adjusted cutting parameter technique to improve the drilling of multi-stacked material. The technique consists in changing the cutting strategy automatically, according to the material being machined. The success of this technique relies on an accurate signal analysis, whatever the process setting. Motor current or thrust force are mostly used as incoming signals. Today, analyses are based on the thresholding method. This consists in assigning lower and upper limits for each type of material. The material is then identified when the signal level is stabilized in between one of the thresholds. Good results are observed as long as signal steps are significantly distinct. This is the case when drilling TA6V-CFRP stacks. However, thrust force level remains roughly unchanged for AA7175-CFRP stacks, leading to overlapping thresholds. These boundary limits may also change with tool geometry, wear condition, cutting parameters, etc. The thresholding method is
Jallageas, Jeremy, Ayfre, Matthieu, Cherif, Mehdi, K'nevez, Jean-Yves, Cahuc, Olivier
Design of ACHEON Thrust and Vector Propulsion System2015-01-242509/15/2015
This paper focuses on the calculation methodology of the thrust of a ACHEON propulsion system, which is based on Coanda effect deflection of thrust. It defines a calculation methodology based on integral equations. The proposed methodology allows an effective calculation of the performances and the force applied on the airplane by such a propulsion system. It will also allow an effective design of the nozzle system and will implement also internal elements with an accurate definition of frictional losses. Outstanding results have been obtained together with general rules for implanting ACHEON propulsion inside an aircraft.
Trancossi, Michele
NDI-Based Controller for Acheon-Based Thrust Vectoring of Aircraft2015-01-246809/15/2015
Nonlinear Dynamic Inversion (NDI) has been previously reported for application to unmanned aircraft systems, due to the inherent attributes of allowing global co-ordinates to be used directly as control inputs. Here, the paper describes a model implementation of an ACHEON propulsion/thrust vectoring system that can be applied to a range of aircraft, with specific emphasis to thrust vectoring of a UAV. Results from the studies show the overall performance is shown to provide improved stability and dynamic characteristics when augmented with additional classical (PI based) control schemes.
Margetts, Rebecca, Bingham, Chris, Smith, Tim
Experimental Identification of the Detachment Point on the ACHEON Thrust-Vectoring Nozzle2015-01-246409/15/2015
Thrust vectoring is an interesting propulsion solution in aeronautic applications due to its fast response, improving aircraft's performance for take-off, landing and flight, and enabling Short/Vertical Take-Off and Landing (S/VTOL). In this context, an attempt to design a radically new concept of thrust vectoring nozzle is in current development. This novel nozzle, called ACHEON, bases the jet deviation control on the interaction of two primary jets of different velocities, where the one with higher velocity entrains the one with lower velocity. Two cylindrical walls are positioned after the two air jets mixing. If the inlet conditions are not symmetric, the Coanda effect on the walls forces the resulting air jet to divert from the symmetry axis. This paper shows the experimental pressure distribution along the Coanda wall for different inlet. Besides the generation of experimental data to be utilized for future CFD simulations validation, the obtained results provides important
Suñol Jiménez, Anna, Yang, Tao, Vucinic, Dean
Development and Performance of a Reduced Order Dynamic Aircraft Model2015-01-241509/15/2015
A reduced order dynamic aircraft model has been created for the purpose of enabling constructive simulation studies involving integrated thermal management subsystems. Such studies are motivated by the increasing impact of on-board power and thermal subsystems to the overall performance and mission effectiveness of modern aircraft. Previous higher-order models that have been used for this purpose have the drawbacks of much higher development time, along with much higher execution times in the simulation studies. The new formulation allows for climbs, accelerations and turns without incurring computationally expensive stability considerations; a dynamic inversion control law provides tracking of user-specified mission data. To assess the trade-off of improved run-time performance against model capability, the reduced order formulation is compared to a traditional six degree-of-freedom model of the same air vehicle. Thrust command comparisons against the higher fidelity model are shown
Shimmin, Kyle, Russell, Greg, Reuter, Robert A., Iden, Steven
Study on Fluidic Thrust Vectoring Techniques for Application in V/STOL Aircrafts2015-01-242309/15/2015
The art and science of thrust vectoring technology has seen a gradual shift towards fluidic thrust vectoring techniques owing to the potential they have to greatly influence the aircraft propulsion systems. The prime motive of developing a fluidic thrust vectoring system has been to reduce the weight of the mechanical thrust vectoring system and to further simplify the configuration. Aircrafts using vectored thrust rely to a lesser extent on aerodynamic control surfaces such as ailerons or elevator to perform various maneuvers and turns than conventional-engine aircrafts and thus have a greater advantage in combat situations. Fluidic thrust vectoring systems manipulate the primary exhaust flow with a secondary air stream which is typically bled from the engine compressor or fan. This causes the compressor operating curve to shift from the optimum condition, allowing the optimization of engine performance. These systems make both pitch and yaw vectoring possible. This paper elucidates
Jain, Samarth, Roy, Soumya, Gupta, Dhruv, Kumar, Vasu, Kumar, Naveen
Self-Adjusting Cutting Parameter Technique for Drilling Multi-Stacked Material2015-01-2502-TEST-REC09/15/2015
This study investigates the self-adjusted cutting parameter technique to improve the drilling of multi-stacked material. The technique consists in changing the cutting strategy automatically, according to the material being machined. The success of this technique relies on an accurate signal analysis, whatever the process setting. Motor current or thrust force are mostly used as incoming signals. Today, analyses are based on the thresholding method. This consists in assigning lower and upper limits for each type of material. The material is then identified when the signal level is stabilized in between one of the thresholds. Good results are observed as long as signal steps are significantly distinct. This is the case when drilling TA6V-CFRP stacks. However, thrust force level remains roughly unchanged for AA7175-CFRP stacks, leading to overlapping thresholds. These boundary limits may also change with tool geometry, wear condition, cutting parameters, etc. The thresholding method is
Jallageas, Jeremy, Ayfre, Matthieu, Cherif, Mehdi, K'nevez, Jean-Yves, Cahuc, Olivier
Prediction of Friction Drive Limit of Metal V-Belt2015-01-113804/14/2015
When fluctuations in the speed of rotation of the drive pulley are transmitted to the driven pulley via the metal V-belt, the transmitted fluctuations become attenuated as friction force approaches a state of saturation. The research discussed in this paper focused on these fluctuations in the speed of rotation and developed an index for the slip state between the belt and the pulleys. The drive and driven pulleys were regarded as a one-dimensional vibrating system connected by elastic bodies, and changes in the state matrix of the system were focused on. It was determined that when all of the eigenvalues in this state matrix become real numbers, slip speed between the belt and the pulleys increases sharply. A method was proposed of estimating this behavior of the eigenvalues from changes in the speed of rotation of the drive and driven pulleys, and indexing the current slip state. Torque fluctuations reproducing the fluctuations produced by an engine were input to the drive pulley
Sakagami, Kyohei
A Method for the Evaluation of the Effectiveness of Turboelectric Distributed Propulsion Power System Architectures2014-01-212009/16/2014
Radical new electrically propelled aircraft are being considered to meet strict future performance goals. One concept design proposed is a Turboelectric Distributed Propulsion (TeDP) aircraft that utilises a number of electrically driven propulsors. Such concepts place a new and significant reliance on an aircraft's electrical system for safe and efficient flight. Accordingly, in addition to providing certainty that supply reliability targets are being met, a contingency analysis, evaluating the probability of component failure within the electrical network and the impact of that failure upon the available thrust must also be undertaken for architecture designs. Solutions that meet specified thrust requirements at a minimum associated weight are desired as these will likely achieve the greatest performance against the proposed emissions targets. This paper presents a Fault Tree Analysis (FTA) based design approach for the electrical system and thrust reliability analysis of TeDP
Shaw, Jennifer C., Norman, Patrick, Galloway, Stuart, Burt, Graeme
A Comparison between Regular and Vibration-Assisted Drilling in CFRP/Ti6Al4V Stack2014-01-223609/16/2014
As aircraft programs currently ramp up, productivity of assembly processes needs to be improved while keeping quality, reliability and manufacturing cost requirements. Efficiency of the drilling process still remains an issue particularly in the case of CFRP/metal stacks: hot and long metallic chips are difficult to remove and often damage the surface of CFRP holes. Low frequency axial vibration drilling has been proposed to solve this issue. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. This paper presents a case of CFRP/Ti6Al4V drilling on a CNC machine where productivity must be increased. A comparison is made between the current regular process and the MITIS drilling process. First the analysis and comparison method is presented. The current process is analyzed and its limits are highlighted. Then the vibration process is implemented and its performances are studied. Both processes are compared according to the
Lonfier, Julian, De Castelbajac, Côme
Smart, In Situ, Wide Range Pressure Sensor for Advanced Engine Controls2014-01-216709/16/2014
Air Force Research Laboratory (AFRL) is pursuing development of advanced, distributed, intelligent, adaptive engine controls and engine health monitoring systems. The goals this pursuit are enhancing engine performance, safety, affordability, operability, and reliability while reducing obsolescence risk. The development of smart, high-bandwidth, high-temperature-operable, wide-range, pressure/temperature multi-sensors, which addresses these goals, is discussed. The resulting sensors and packaging can be manufactured at low cost and operate in corrosive environments, while measuring temperatures up to 2,552 °F (1,400 °C) with simultaneous pressure measurements up to 1,000 psi (68 atm). Such a sensor suite provides unprecedented monitoring of propulsion, energy generation, and industrial systems. The multi-sensor approach reduces control system weight and wiring complexity, design time, and cost, while increasing accuracy and fault tolerance. In situ pressure sensors reduce size and
Usrey, Michael, Harsh, Kevin, Brand, Alexander, McKown, R. Steve, Behbahani, Alireza
Experimental Investigation of Asymmetrical Capacitors for Electric Propulsion2014-01-222109/16/2014
Investigation into electric propulsion continues to be an area of hopeful research since the pioneering age of aviation. However, more recent global awareness of carbon emissions on the planet and the desire to create more efficient systems has reinvigorated new life into the field. Experimental studies on electric propulsion by virtue of asymmetrical electrodes, on a micro scale, have yielded potentially superior efficiency ratings when compared to currently adopted methods. The observed effect is that asymmetrical electrodes which are subjected to high voltage and are separated by a fluid dielectric medium experience thrust towards the smaller electrode. This method of propulsion is unique and possesses several features that differentiate it from conventional methods of propulsion. One major benefit of this phenomenon is that the electrical energy is directly converted into a mechanical force without the requirement of any moving components. Such a method of would only require a high
Matsoukas, George, Ahmed, Noor
Advanced Composite Thrust Chambers for In-Space PropulsionTBMG-2030708/01/2014
Radiation-cooled, bipropellant thrust chambers are being used for in-space propulsion. To increase the performance of radiation-cooled engines, improved chamber materials are needed that will allow higher operating conditions (pressure and temperature), better resistance to oxidation, and reduced mass. During this effort, an innovative composite thrust chamber is being developed that will incorporate advanced hafnium oxide and iridium liner techniques as well as replacing the expensive, high-density rhenium with a low-mass carbon-carbon (C–C) structural wall.
Computational Study of Coanda Adhesion Over Curved Surface2013-01-230209/17/2013
This paper presents a set of numerical computations with different turbulence model on an air jet flowing tangentially over the curved surface. It has been realized that jet deflection angle and the corresponding thrust are important parameter to determine with great care. Through the grid independence analysis, it has been found that without resolution of the viscous sub-layer, it is not possible to determine the computationally independent angle of jet deflection and boundary layer thickness. The boundary layer analysis has been performed at different radius of curvature and at jet Reynolds number ranging from approximately about 2400-10,000. The boundary layer thickness has been determined at the verge of separation and found a relation with the radius of curvature and jet Reynolds number. The skin-friction coefficient has been also studied at the verge of separation in relation to the surface radius and jet Reynolds number. In this research work, the inter-relation between flow and
Subhash, Maharshi, Dumas, Antonio
Defining Requirements for the Implementation of Interconnected Generation in Future Civil Aircraft2013-01-212509/17/2013
In addition to providing thrust, the engines on conventional civil jet airliners generate power for on-board systems and ancillary loads in the form of pneumatic, hydraulic and electrical power. Reduced fuel-burn and efficiency targets have driven the move towards More Electric Aircraft (MEA) technology which seeks to replace hydraulic and pneumatic loads with electrical equivalents. This technological shift, in conjunction with a growing electrical power load per passenger in general, has greatly increased the electrical power demands of aircraft in recent years - over 1 MVA for the Boeing 787 for example. With increasing fuel prices, there is a growing need to optimise efficiency of power extraction from the aircraft engines for the electrical system and loads. In particular, the utilisation of multi-shaft power off-takes, interconnected generation and power sharing between shafts is thought to offer potentially significant engine operability and fuel efficiency benefits. This paper
Mackenzie-Leigh, Gordon, Norman, Patrick, Galloway, Stuart, Burt, Graeme, Orr, Eddie
Algorithmic Approach for Algebraic Derivation of Time and Distance to Speed during Variable Acceleration2013-01-232409/17/2013
The take-off of a departing aircraft is subjected to varying forces, the largest of which are function of the speed of the aircraft itself: the thrust of a jet engine, the aerodynamic drag of the airframe are essentially polynomial function of the airspeed. First principle field performance determination has relied for the last half century on stepwise integration, a brute force approach that requires properly tuned integration steps, which has the benefit of being fairly reliable but with relatively low computational efficiency. An alternate, mathematically more formal approach would be to algebraically integrate an accelerative function combining all the forces in presence. While comparatively complex, the derivation of the solution equations permits fast and accurate integration between boundary conditions, which could be orders of magnitude more efficient than stepwise integration, even with relatively high degree of polynomial force functions, while being essentially free of any
Goudreault, Vincent
Numerical Investigation of Rotor Performance Surrounded with Wind Fence using Actuator Model based on OpenFOAM2013-01-224409/17/2013
The purpose of this study is to investigate the effects of the size and location of wind fences on the rotor performance to avoid as well as quantify any adverse effects of outside wind on the measurement accuracy. To this end, firstly, a novel actuator disk method is developed which couples open source CFD code named OpenFOAM with blade element method and rotor flapping equations. Secondly, the parametric studies are conducted with respect to wind fence configurations which contain fence radius, inlet/outlet duct size and location etc. For quantitative evaluation of rotor performance variation according to inlet/outlet duct size, the mass flow and momentum rate on the ducts are. The rotor performance variation depending on the wind fence configuration is examined and consequently parametric study cases are classified according as calculated rotor thrust coefficient. Moreover, it is explained the difference of flow field in wind fence by demonstrating the pressure coefficient. Finally
Kim, Taewoo, Oh, Sejong, Yee, Kwanjung
PROPELLER SHAFT ENDS, DUAL ROTATION (PROPELLER SUPPLIED BEARING)ARP375D (Current)02/05/2013
E-25 General Standards for Aerospace and Propulsion Systems
PROPELLER ATTACHMENT - NOSE MOUNTEDARP277B (Current)02/05/2013
E-25 General Standards for Aerospace and Propulsion Systems
Less-Invasive Ventricular Assist Device for Late-Stage Heart FailureTBMG-1550101/01/2013
The first full-support, miniaturized ventricular assist device designed to be placed in the pericardial space, was approved by the FDA in late November. HeartWare International, Inc., Framingham, MA, an innovator of less invasive, miniaturized circulatory support technologies to treat advanced heart failure, said that its Ventricular Assist System was approved as a bridge to cardiac transplantation in patients who are at risk of death from refractory end-stage left ventricular heart failure.
Fuel Consumption and Power Performance Prediction in Outboard Motors for High-Speed Planing Boats using CFD Simulation2012-32-009910/23/2012
Predicting fuel consumption and performance of an outboard motor for a high speed small planing boat are numerically challenging. The propeller is one of the most popular propulsion systems used for outboard motors. We focused our attention on the fact that the thrust performance of a propeller has a major impact on cruising fuel consumption and performance. We believe that we can numerically predict cruising fuel consumption, which has conventionally been estimated through experiential means, using accurate thrust performance measurements via CFD simulation without cavitations model. This study aims to develop a simulator that could quantitatively predict cruising fuel consumption and performance of an outboard motor used for a high speed small planing boat. After comparing the CFD simulation of propellers against the results of model tests, the simulated results are in good agreement with the experimental results. In order to evaluate the accuracy of the fuel consumption and
Kurioka, Shunsuke
Propeller Shaft Ends - Dual Rotation (Engine Supplied Bearing)X-AIR18A (Current)10/19/2012
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.
E-25 General Standards for Aerospace and Propulsion Systems
ASCENT ProgramTBMG-1387306/01/2012
The ASCENT program solves the three-dimensional motion and attendant structural loading on a flexible vehicle incorporating, optionally, an active analog thrust control system, aerodynamic effects, and staging of multiple bodies.
MATLAB Stability and Control Toolbox Trim and Static Stability ModuleTBMG-1263701/01/2012
MATLAB Stability and Control Toolbox (MASCOT) utilizes geometric, aerodynamic, and inertial inputs to calculate air vehicle stability in a variety of critical flight conditions. The code is based on fundamental, non-linear equations of motion and is able to translate results into a qualitative, graphical scale useful to the non-expert.
NASA System-Level Design, Analysis and Simulation Tools Research on NextGen2011-01-271610/18/2011
A review of the research accomplished in 2009 in the System-Level Design, Analysis and Simulation Tools (SLDAST) of the NASA's Airspace Systems Program is presented. This research thrust focuses on the integrated system-level assessment of component level innovations, concepts and technologies of the Next Generation Air Traffic System (NextGen) under research in the ASP program to enable the development of revolutionary improvements and modernization of the National Airspace System. The review includes the accomplishments on baseline research and the advancements on design studies and system-level assessment, including the cluster analysis as an annualization standard of the air traffic in the U.S. National Airspace, and the ACES-Air MIDAS integration for human-in-the-loop analyzes within the NAS air traffic simulation.
Bardina, Jorge
Orbital Drilling Machine for One Way Assembly in Hard Materials2011-01-274510/18/2011
In Aeronautic industry, when we launch a new industrialization for an aircraft sub assembly we always have the same questions in mind for drilling operations, especially when focusing on lean manufacturing. How can we avoid dismantling and deburring parts after drilling operation? Can a drilling centre perform all the tasks needed to deliver a hole ready to install final fastener? How can we simplify specific jigs used to maintain parts during drilling operations? How can we decrease down-time of the drilling centre? Can a drilling centre be integrated in a pulse assembly line? How can we improve environmental efficiency of a drilling centre? It is based on these main drivers that AIRBUS has developed, with SPIE and SOS, a new generation of drilling centre dedicated for hard materials such as titanium, and high thicknesses. The first application was for the assembly of the primary structure of A350 engine pylons. The main solution that was implemented meeting several objectives was the
Ple, Pascal, David, Florian, Gabory, Jean-Francois, Van Damme, Damien
Seaplane Conceptual Design2011-01-269610/18/2011
The seaplane industry expanded widely between the periods of World War I and World War II. Seaplanes were commonly used by military water rescue missions, reconnaissance and anti-submarine warfare7. However, with the introduction of new efficient aircraft designs and suitable landplane infrastructure, the use of the seaplanes declined. No new advanced designs have been created, and most seaplanes existing these days are approaching its final operating life. The purpose of this paper is to introduce a new advance concept design for a seaplane, in which costs caused by manufacturing and regulations will be reduce. In order to reduce these costs, existing aircrafts presented will be configured into a seaplane by adding a floating device. Many proposed ideas were analyzed, but due to the complexity and high costs of some of these, it was decided to use retractable floats to reduce drag and a trimaran boat hull to increase hydrodynamic performance of the seaplane. Based on the results, the
Canamar, Alan Leonel, Smrcek, Ladislav
Certification of Engine Health Management Systems: Guidelines for Selecting Software Assurance Levels2011-01-270410/18/2011
The use of Engine Health Management (EHM) systems has been growing steadily in both the civilian and the military aerospace sectors. Barring a few notable exceptions (such as certain temperature and thrust margin monitoring) regulatory authorities around the world have not required these systems to be certified in any way. This is changing rapidly. New airframes and engines are increasingly being designed with the assumption that EHM will be an integral part of the way customers will operate these assets. This leads to a need for better guidelines on how such systems should be certified. The SAE E-32 committee on Propulsion System Health Monitoring is leading an industry-wide effort to develop a set of guidelines for certifying EHM systems. Since software plays a critical role in these systems, and since the hardware and the system-level aspects of certification have been covered thoroughly by other standards such as ARP 4754A, the emphasis of this initial effort is EHM software, and
Rajamani, Ravi, Waters, Nicholas
Software Development Standard Processes (SDSP)TBMG-1013706/01/2011
A JPL-created set of standard processes is to be used throughout the lifecycle of software development. These SDSPs cover a range of activities, from management and engineering activities, to assurance and support activities. These processes must be applied to software tasks per a pre- scribed set of procedures. JPL’s Software Quality Improvement Project is currently working at the behest of the JPL Software Process Owner to ensure that all applica- ble software tasks follow these procedures.The SDSPs are captured as a set of 22 standards in JPL’s software process domain. They were developed in-house at JPL by a number of Subject Matter Experts (SMEs) residing primarily with- in the Engineering and Science Directorate, but also from the Business Operations Directorate and Safety and Mission Success Directorate. These prac- tices include not only currently per- formed best practices, but also JPL- desired future practices in key thrust areas like software architecting and soft- ware
Software Development Standard Processes (SDSP)TBMG-TB-01013706/01/2011
A JPL-created set of standard processes is to be used throughout the lifecycle of software development. These SDSPs cover a range of activities, from management and engineering activities, to assurance and support activities. These processes must be applied to software tasks per a pre- scribed set of procedures. JPL’s Software Quality Improvement Project is currently working at the behest of the JPL Software Process Owner to ensure that all applica- ble software tasks follow these procedures.
MASCOT — MATLAB Stability and Control ToolboxTBMG-955404/01/2011
MASCOT software was created to provide the conceptual aircraft designer accurate predictions of air vehicle stability and control characteristics. The code takes as input mass property data in the form of an inertia tensor, aerodynamic loading data, and propulsion (i.e. thrust) loading data. Using fundamental non-linear equations of motion, MASCOT then calculates vehicle trim and static stability data for any desired flight condition. Common predefined flight conditions are included. The predefined flight conditions include six horizontal and six landing rotation conditions with varying options for engine out, crosswind and sideslip, plus three takeoff rotation conditions. Results are displayed through a unique graphical interface developed to provide stability and control information to the conceptual design engineers using a qualitative scale indicating whether the vehicle has acceptable, marginal, or unacceptable static stability characteristics.
Nanoengineering for Solid-State LightingTBMG-916302/18/2011
This report summarizes results from a three-year Laboratory Directed Research and Development (LDRD) project. The collaborative effort of researchers from Sandia National Laboratories and Rensselaer Polytechnic Institute was supported by Sandia’s National Institute for Nano-Engineering and focused on the study and application of nanoscience and nanoengineering concepts to improve the efficiency of semiconductor light-emitting diodes (LEDs) for solid-state lighting applications.
Nanoengineering for Solid-State LightingTBMG-1434302/01/2011
Sandia National Laboratories, Albuquerque, NM Rensselaer Polytechnic Institute, Troy, NY
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