Browse Topic: Propellers and rotors

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Design optimization of the propeller shaft and transfer case for high-speed 4WD vehicles2026-26-0343To be published on 01/16/2026
Nowadays, vehicle enthusiasts often vary their driving patterns, ranging from driving at very high speeds to off-roading. Due to these driving patterns, 4WD vehicle demand is continuously growing day by day. A 4WD vehicle used to have better traction control with enhanced stability. The 4WD vehicle performance and reliability at high speed are critically influenced by driveline stiffness and natural frequency. Driveline stiffness and natural frequency are very critical parameter for high-speed vehicles, that significantly influenced by the propeller shaft and transfer case. This study focuses on the design optimization of the transfer case and critical frequency of propeller shafts to enhance vehicle performance at high speeds. The analysis begins with a comprehensive study of the factors affecting power transfer path, transfer case stiffness, critical frequency, including material properties, propeller shaft geometry and the boundary conditions. Advanced computational methods are
Kumar, Sarvesh, Yadav, Sahdev, S, Manickaraja, Sanjay, L, Kanagaraj, Pothiraj, Jain, Saurabh Kumar, Deole, Subodh M
Optimization of Propeller shaft design to eliminate Launch Undulation (Lateral shake) and Vibration level2026-26-0334To be published on 01/16/2026
During vehicle launches in 1st gear, a lateral shake (undulation) and a pronounced metallic hitting noise were observed in the underbody. The noise was identified as the propeller shaft's second universal joint (UJ) yoke striking the fuel tank mounting bracket. Sensitivity to these issues varied with acceleration inputs: light pedal input during a normal 1st gear launch on a flat road resulted in minimal undulation, whereas wide open throttle (WOT) conditions in 1st gear produced significant lateral shake and intensified hitting noise. Further investigation revealed that the problem persists across all gears and occurs consistently during normal driving conditions, with continuous impact between the propeller shaft yoke and the fuel tank mounting bracket. Extensive experimental measurements at the vehicle level indicated that these issues were primarily caused by the center-mounted propeller shaft joint deviating from its central position and rotating eccentrically under torque. This
Sanjay, L, S, Manickaraja, Kumar, Sarvesh, Kanagaraj, Pothiraj, Senthil Raja, T, B, Prem Prabhakar, M, Kiran
Operating Characteristics of an Automotive Adjustable-Field Permanent Magnet Motors with 3D Magnetic Paths and Asymmetric Magnet Arrangement2024-32-002704/18/2025
This paper describes a three-dimensional structure of an adjustable field magnetization permanent magnet (PM) motor and a high-power density rotor structure with asymmetric permanent magnet arrangement for both high torque and high efficiency operation in the high speed and low torque range. 3D-FEA has confirmed that it is possible to achieve both high torque density and adjustable field magnetization. Load testing using the prototype proposed motor confirmed that high motor efficiency can be achieved even during high-speed operation.
Hiyoshi, Yutaro, Doi, Kotaro, Noguchi, Toshihiko
Quantification of the Aerodynamic Interference for Counter-Rotating Coaxial Rotors In-Ground EffectF-0080-2024-000405/07/2024
The performance of a coaxial rotor hovering in-ground effect (IGE) is compared against the out-of-ground effect (OGE) condition to quantify the rotor-ground interaction and against an isolated rotor IGE at equivalent blade loading to quantify the rotor-rotor interaction. It is observed that the performance of the coaxial rotor improves when it hovers IGE. However, the rotor-rotor and rotor-ground interactions compete, which affects the performance of the coaxial rotor. This paper aims to quantitatively measure the aerodynamic interactions of the CCR in IGE by developing a theoretical framework based on momentum theory. This formulation introduced induced power factors to understand the aerodynamic interactions of a CCR operating IGE. The performance measurements show that the rotor-ground interaction in the CCR system behaved similarly to a single rotor operating in IGE conditions. The interactional effects significantly influence the individual rotors as the rotor-rotor interactions
Moore, Zachary, Silwal, Lokesh, Vijayaraj, Aditya, Raghav, Vrishank
Measurement uncertainty and its influence on e-Drive optimization applications2024-26-009701/16/2024
This paper gives insights in the theoretical measurement uncertainty of E-Drive rotor position dependent results, like Id and Iq calculations, done by a modern propulsion power analyzer (PA). The calculation of Id and Iq is fundamental to perform control optimization and application tasks for an E-Drive system. In order to optimize the E-Drive system application towards e.g. best efficiency, best performance, or improved NVH the importance of the testing toolchain is described: a power analyzer delivering the required results, an automation system, and a Design of Experiment tool to set improved target values. Consequently, inverters applications featuring field-oriented control (FOC) with permanent magnet synchronous machines (PMSM) are updated with a chosen control strategy. For achieving a certain behavior of an E-Drive, different degrees of freedom in the Inverter Control Unit are available; Lookup tables Id and Iq represent two fundamental application labels to be considered
Platzer, Thomas, Fechter, Michael, Kammerstetter, Heribert, Kolb, Philipp
An Aerodynamic Equation of State—Part I: Introduction and Aerospace Applications - QA Test Tatsiana01-17-01-000104/19/2023
Abstract In subsonic aircraft design, the aerodynamic performance of aircraft is compared meaningfully at a system level by evaluating their range and endurance, but cannot do so at an aerodynamic level when using lift and drag coefficients, CL and CD , as these often result in misleading results for different wing reference areas. This Part I of the article (i) illustrates these shortcomings, (ii) introduces a dimensionless number quantifying the induced drag of aircraft, and (iii) proposes an aerodynamic equation of state for lift, drag, and induced drag and applies it to evaluate the aerodynamics of the canard aircraft, the dual rotors of the hovering Ingenuity Mars helicopter, and the composite lifting system (wing plus cylinders in Magnus effect) of a YOV-10 Bronco. Part II of this article applies this aerodynamic equation of state to the flapping flight of hovering and forward-flying insects. Part III applies the aerodynamic equation of state to some well-trodden cases in fluid
Burgers, Phillip
An Aerodynamic Equation of State—Part I: Introduction and Aerospace Applications - QA Test Tatsiana01-17-01-0001-TEST-REC04/19/2023
Abstract In subsonic aircraft design, the aerodynamic performance of aircraft is compared meaningfully at a system level by evaluating their range and endurance, but cannot do so at an aerodynamic level when using lift and drag coefficients, CL and CD , as these often result in misleading results for different wing reference areas. This Part I of the article (i) illustrates these shortcomings, (ii) introduces a dimensionless number quantifying the induced drag of aircraft, and (iii) proposes an aerodynamic equation of state for lift, drag, and induced drag and applies it to evaluate the aerodynamics of the canard aircraft, the dual rotors of the hovering Ingenuity Mars helicopter, and the composite lifting system (wing plus cylinders in Magnus effect) of a YOV-10 Bronco. Part II of this article applies this aerodynamic equation of state to the flapping flight of hovering and forward-flying insects. Part III applies the aerodynamic equation of state to some well-trodden cases in fluid
Burgers, Phillip
An Aerodynamic Equation of State—Part I: Introduction and Aerospace Applications01-17-01-000104/19/2023
In subsonic aircraft design, the aerodynamic performance of aircraft is compared meaningfullyby evaluating their range and endurance, but cannot do so atwhen using lift and drag coefficients,and, as these often result in misleading results for different wing reference areas. This Part I of the article (i) illustrates these shortcomings, (ii) introduces a dimensionless number quantifying the induced drag of aircraft, and (iii) proposes anfor lift, drag, and induced drag and applies it to evaluate the aerodynamics of the canard aircraft, the dual rotors of the hoveringMars helicopter, and the composite lifting system (wing plus cylinders in Magnus effect) of a YOV-10. Part II of this article applies this aerodynamic equation of state to the flapping flight of hovering and forward-flying insects. Part III applies the aerodynamic equation of state to some well-trodden cases in fluid mechanics found in fluid-mechanics textbooks.
Burgers, Phillip
Re-imagining Brake Rotor Thermal Fatigue Testing to Relate to Field Use2022-01-116309/19/2022
The validation of brake rotors has remained, to this day, heavily reliant on “Thermal Abuse” or “Thermal Cracking” type testing, with many procedures so dated that most engineers active in the industry today cannot even recall the origin of the test. These procedures - of which there are many variants - all share the trait of greatly accelerating durability testing by performing repeated high power (high speed and high deceleration) brake applies to drive huge temperature gradients and internal stress, and often allowing the rotor to get very hot, to where the strength of the material from which the rotor is constructed is significantly degraded. There is little debate about whether these procedures work; by and large rotor durability issues in the field are extremely rare. However, without the connection to the duty cycle in the field, it is extremely difficult to interpret results (especially since many standards allow significant cracking before a failure is declared), and this can
Antanaitis, David, Langhardt, Jerry
Design and Computational Investigations of Aerobot for Titan with maneuverability using momentum wheel and propeller equipped with droppable weather stations 2022-26-119105/26/2022
Titan, Saturn’s largest moon and the only celestial body which is found to have a landmass composed of liquid hydrocarbons. Nitrogen – The building block of all life that exists on earth is found to be abundant in Titan’s atmosphere of up to 97%. Aerobots provide a great platform for exploring a celestial body with an atmosphere such as Titan. They have modest power requirements, longer mission duration, and can cover a longer distance in a shorter time. They are powered by Radioisotope Thermoelectric Generator for optimal mission life. Aerobot’s altitude can be altered by varying the temperature of the air inside the balloon and yaw can be controlled using Reaction Wheel and a motor-driven propeller for forwarding thrust. The proposed Aerobot will be equipped with four miniature deployable fixed weather stations that can be dropped from the aerobot to titan’s surface. They can be deployed at diverse locations such as the equator and Polar Regions to deeply explore the Titan’s climate
Raja, Manoj Kumar, Sivasankaran, Abinash Nataraj, Saravana Mohan, Haribalan, Thangavel, Sabari, R, Vijayanandh, Gnanasekaran, Raj Kumar
Design and Parametric Investigations on Various Propellers for Nature Inspired Unmanned Amphibious Vehicle2022-26-117405/26/2022
Unmanned Amphibious Vehicle (UAV) is an integrative working environments based vehicle, which doesn’t allocate the place for onboard pilots. Mostly, unmanned amphibians have been controlled through pre-provided algorithms in the predestined paths. Aerodynamic and hydrodynamic working conditions are the compositions of aforesaid integrative environments, wherein the possible lifespan affecting failure of UAV may chance to happen in a high manner. Thus, the multidisciplinary investigation on UAV and it's every component needs to be done in order to pick the suitable UAV parts for both missions executing conditions. This work deals the comprehensive computational investigations on a different number of blades equipped propellers for the proposed cum nature-inspired UAV under aerodynamic and hydrodynamic loading conditions. Three different propellers are uniquely constructed based on the aerodynamic environment reference with the guidance of analytical formulae and thereafter modeling
R, Vijayanandh, Mathaiyan, Vijayakumar, Raji, Arul Prakash, Madasamy, Senthil Kumar, Gnanasekaran, Raj Kumar
Augmentation of Gas-Turbine Performance Using Inlet Air Cooling and Turbine Blade Cooling: A Thermodynamic Approach2021-01-003103/02/2021
A systematic and comprehensive first law analysis of a cooled gas turbine cycle subjected to vapor compressor inlet air cooling (VC-IAC) has been conducted in our study. Film air cooling technique has been implemented to cool the gas turbine (GT) buckets. The gas turbine is subjected to variation of various operating and ambient parameters and the corresponding effect is analyzed to find out the optimal one. The integration of VC-IAC has been reported to further enhance the plant specific work and plant efficiency of gas turbine cycle, the enhancement being higher in regions having a hot and dry climate. This increase in cycle performance due to VC-IAC has been found superior in case of bucket cooled GT cycle when compared to uncooled one. It has further been witnessed that the plant specific work increases by more than 0.35 % and the plant efficiency increases by little above 0.1 % for every 1o C drop in CIT. The work ratio representing the excess of work of turbine over work of
Mishra, Alok, Srivastava, Anshuka, Mohapatra, Alok Kumar
Designation of Direction of Rotation of Helicopter RotorsARP570B (Current)01/14/2021
S-12 Powered Lift Propulsion Committee
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.
Wear Performances of Gray Cast Iron Brake Rotor with Plasma Electrolytic Aluminating Coating against Different Pads2020-01-162310/05/2020
Gray cast iron brake rotor experiences substantial wear during braking and contributes largely to the wear debris emissions. Surface coating on the gray cast iron rotor represents a trending approach dealing with the problems. In this research, a new plasma electrolytic aluminating (PEA) process was used for preparing an alumina-based ceramic coating with metallurgical bonding to the gray cast iron. Three different types of brake pads (ceramic, semi-metallic and non asbestos organic (NAO)) were used for tribotests. Performances of PEA coatings vs. different brake pad materials were comparatively investigated with respect to their coefficients of friction (COFs) and wear. The PEA-coated brake rotor has a dimple-like surface which promotes the formation of a thin transferred film to protect the rotor from wear. The transferred film materials come from the wear debris of the pads. The secondary plateaus are regenerated on the brake pads through compacting wear debris of the pads. The wear
Cai, Ran, Zhang, Jingzeng, Tjong, Jimi, Nie, Xueyuan
Driveline Optimization to Reduce the Noise in 4X4 Heavy Commercial Vehicle2020-01-224609/15/2020
One of the important factors strongly required by customers nowadays is lower noise and vibration in vehicle. In this paper the prime focus is made on the study of effect of driveline angles on the noise and vibration behavior in a 4X4 configuration commercial vehicle. The impact of propeller shaft angles in the transfer of driveline excitations to the transmission and the resulting noise and vibration is studied. An abnormal noise was perceived from transmission and the root cause was investigated for the same. These excitations were high due to the higher driveline angles as this was design requirement to maintain higher ground clearance. A two-stage approach was adopted to modify the effect (transmission) and cause (propeller shaft angle) there by reducing the abnormal noise and vibration perceived in the vehicle. First the driveline angles were reduced to optimum and secondly, the axle was modified suitably so that the required lower angle of propeller shafts is achieved without
Inavolu, Nagasuresh, Paulraj, Jebasingh A, M, Jaganmohan Rao
Minimization of Electric Heating of the Traction Induction Machine Rotor2020-01-056204/14/2020
The article solves the problem of reducing electric power losses of the traction induction machine rotor to prevent its overheating in nominal and high-load modes. Electric losses of the rotor power are optimized by the stabilization of the main magnetic flow of the electric machine at a nominal level with the amplitude-frequency control in a wide range of speeds and increased loads. The quasi-independent excitation of the induction machine allows us to increase the rigidity of mechanical characteristics, decrease the rotor slip at nominal loads and overloads and significantly decrease electrical losses in the rotor as compared to other control methods. The article considers the technology of converting the power of individual phases into a single energy flow using a three-phase electric machine equivalent circuit and obtaining an energy model in the form of equations of instantaneous active and reactive power balance. The quasi-independent excitation of the induction machine is
Nikiforova, Elena, Smolin, Victor, Gladyshev, Sergey
How to Install Coiled Spring PinsTBMG-3660404/01/2020
Coiled Spring Pins20AERP04_0104/01/2020
What Do They Do? How Do You Install Them? Of the hundreds of different types of fasteners used within the aerospace industry, the coiled spring pin was specifically invented as a solution to a “pinning” issue related to securing jet engine turbine blade assemblies back in the 1940s. No other fastener (pin, bolt, rivet, etc.) was strong enough to resist the forces generated during use that was also flexible enough to enable the pin to absorb shock and vibration to isolate the loads from the host material. It is this unique combination of strength and flexibility that enables the coiled pin to preserve the integrity of the hole and ensure that assemblies subject to dynamic loading stay intact. Today, coiled spring pins are used extensively throughout the aerospace industry for a wide variety of purposes. They are used to fasten two or more components together within evacuation slide mechanisms and cargo straps; they are used as hinge pins within interior latch mechanisms in overhead bin
Performance of Isolated UAV Rotors at Low Reynolds Number2020-01-004603/10/2020
Vertical takeoff and landing vehicle platforms with many small rotors are gaining importance for small UAVs as well as distributed electric propulsion for larger vehicles. To predict vehicle performance, it must be possible to gauge interaction effects. These rotors operate in the less-known regime of low Reynolds number, with different blade geometry. As a first step, two identical commercial UAV rotors from a flight test program are studied in isolation, experimentally and computationally. Load measurements were performed in Georgia Tech’s 2.13 m × 2.74 m wind tunnel. Simulations were done using the RotCFD solver which uses a Navier-Stokes wake computation along with rotor-disc loads calculation using low-Reynolds number blade section data. It is found that in hover, small rotors available in the market vary noticeably in performance at low rotor speeds, the data converging at higher RPM and Reynolds number. This is indicative of the high sensitivity of low-Re rotor flows to minor
Tomar, Yashvardhan, Shukla, Dhwanil, Komerath, Narayanan
Performance of Isolated UAV Rotors at Low Reynolds Number2020-01-004603/10/2020
Vertical takeoff and landing vehicle platforms with many small rotors are gaining importance for small UAVs as well as distributed electric propulsion for larger vehicles. To predict vehicle performance, it must be possible to gauge interaction effects. These rotors operate in the less-known regime of low Reynolds number, with different blade geometry. As a first step, two identical commercial UAV rotors from a flight test program are studied in isolation, experimentally and computationally. Load measurements were performed in Georgia Tech’s 2.13 m × 2.74 m wind tunnel. Simulations were done using the RotCFD solver which uses a Navier-Stokes wake computation along with rotor-disc loads calculation using low-Reynolds number blade section data. It is found that in hover, small rotors available in the market vary noticeably in performance at low rotor speeds, the data converging at higher RPM and Reynolds number. This is indicative of the high sensitivity of low-Re rotor flows to minor
Tomar, Yashvardhan, Shukla, Dhwanil, Komerath, Narayanan
Attack Reconnaissance HelicopterTBMG-3606302/01/2020
Bell Textron Inc Fort Worth, TX +1 817-280-2011
Adaptive Spatial Resolution Enables Focused Fiber Optic SensingTBMG-3572512/01/2019
This advanced fiber optic sensing innovation developed at NASA’s Armstrong Flight Research Center offers a unique combination of high-resolution processing and flexibility. The algorithm was originally developed to enhance Armstrong’s multi-patented Fiber Optic Sensing System (FOSS). With over 2,000 sensors per fiber, FOSS enables thousands of high-resolution measurements at once including strain, shape, temperature, pressure, and more.
Advanced Assembly Solutions for the Airbus RACER Joined-Wing Configuration2019-01-188409/16/2019
The Rapid And Cost Effective Rotorcraft (RACER) is being developed by Airbus Helicopters (AH) to demonstrate a new Vertical Take-Off and Landing configuration to fill the mobility gap between conventional helicopters and aeroplanes. RACER is a compound rotorcraft featuring wings and multiple rotors. The wing arrangement suggested by AH is defined as a staggered bi-plane joined configuration with an upper and a lower straight wing, either side of the fuselage, connected at their outboard extent to form a triangular structure. The ASTRAL consortium, consisting of the University of Nottingham and GE Aviation Systems, are responsible for the design, manufacture, assembly and testing of the wings. Producing an optimised strategy to assemble a joined-wing configuration for a passenger carrying rotorcraft is challenging and novel. The objective of this work concerns all aspects of assembling the joined-wing structure. The joined-wing and fuselage structures will be produced independently and
Bainbridge, David, Bacharoudis, Konstantinos, Cini, Andrea, Turner, Alison, Popov, Atanas, Ratchev, Svetan
Disc Thickness Variation (DTV) Operational Measurement and Influence on the Overall Vehicle Roughness2019-01-211009/15/2019
The brake disc or rotor design is one of the main concerns in the development of the vehicle brake system. One of the key factors of its drawing and manufacture is related with the thermo-mechanical deformation that can transmit further vibrations to the complete vehicle. This phenomenon, called brake judder or roughness, can appear in both cold and hot brake conditions, the latter being especially affected by the thermal factor. The evolution of the disc shape fluctuation and Disc Thickness Variation (DTV) is usually illustrated before and after a test, reflecting typically the same output. However, the real transient disc behavior during these phases is rarely measured and is difficult to determine. The reality is that most of the time, some unexpected deformations may appear, these being the final root cause of the excitation of judder vibration. During the cold judder, the disc starts at a low temperature and controlled DTV, which corresponds to the disc’s natural shape and is only
Ferrer, Bernat
The Analysis of Brake Squeal Noise Related to the Friction Properties of Brake Friction Materials2019-01-213209/15/2019
The friction properties related to squeal noise was analyzed with the development histories and simplified computational method. Firstly, the development histories were investigated especially focusing on the case which the friction materials were modified to improve squeal noise occurrence. Based on the histories, the friction properties of selected friction materials were newly measured using dynamometer. The average friction coefficient levels, torque oscillations, the increment of friction coefficient during full-stop, and etc. were compared with the squeal noise occurrence, and the results showed that increase of friction properties cause production of squeal noise. The result suggested that the size of friction energy was important factors related to triggering the squeal noise. Also, the contact conditions between rotor disc and friction materials were significant factors deciding the noise occurrence. We performed simplified computational analysis using MATLAB program to prove
Lee, Sang-mok, Woo, Jung Hoon, Cho, Younggu, Kim, Dong Won
CH148 Icing Flight Test Performance Data Correlation2019-01-199106/10/2019
This paper presents results of correlation of an empirical code to CH148 Cyclone® icing flight test performance data. Predicted icing main rotor torque penalties, generated using the Sikorsky Generalized Rotor Performance (GRP) model with the integral DELICE icing performance module, are compared to flight test results. DELICE methodology adjustments are shown that lead to CH148 test data correlation and improved correlation to previously-examined S-92A™ icing flight test performance data. Finally, a comparison of results between GRP and Sikorsky-Maryland FreeWake is shown, providing an indication of the influence of rotor wake methodology on icing model correlation.
Griffiths, Daniel
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
An Ice Shedding Model for Rotating Components2019-01-200306/10/2019
A CFD simulation methodology is presented to evaluate the ice that sheds from rotating components. The shedding detection is handled by coupling the ice accretion and stress analysis solvers to periodically check for the propagation of crack fronts and possible detachment. A novel approach for crack propagation is highlighted where no change in mesh topology is required. The entire computation from flow to impingement, ice accretion and crack analysis only requires a single mesh. The accretion and stress module are validated individually with published data. The analysis is extended to demonstrate potential shedding scenarios on three complex industrially-relevant 3D cases: a helicopter blade, an engine fan blade and a turboprop propeller. The largest shed fragment will be analyzed in the context of FOD damage to neighboring aircraft/component surfaces.
Nilamdeen, Shezad, Zhang, Yue, Ozcer, Isik, Baruzzi, Guido S.
Multi-Shot Icing Simulations with Automatic Re-Meshing2019-01-195606/10/2019
A full-automated CFD mesh generation technique has been developed and implemented for 3-D aircraft icing simulations to permit robust 45-minute ice accretion simulations in support of icing certification campaigns. The changes in the shape of the aircraft surfaces due to accreting ice and their effects on the air and droplet flow are accounted for in a quasi-steady manner by subdividing the total icing time into sequential steps of shorter duration, updating the computational grid at each step. This “multi-shot” ice accretion approach requires robust and accurate grid re-meshing for it to be embedded in engineering design and analysis workflows. ANSYS FENSAP-ICE has been coupled to Fluent Meshing to take advantage of generic and highly automated surface displacement and mesh wrapping tools. A wide spectrum of geometries is supported, ranging from full-size aircraft to air data probes, turbomachinery components, rotors and propellers. With this technology, obtaining 45-minute ice shapes
Ozcer, Isik, Switchenko, David, Baruzzi, Guido S., Chen, Jian
Vibro-Acoustic Analysis for Modeling Propeller Shaft Liner Material2019-01-156006/05/2019
In recent truck applications, single-piece large-diameter propshafts, in lieu of two-piece propshafts, have become more prevalent to reduce cost and mass. These large-diameter props, however, amplify driveline radiated noise. The challenge presented is to optimize prop shaft modal tuning to achieve acceptable radiated noise levels. Historically, CAE methods and capabilities have not been able to accurately predict propshaft airborne noise making it impossible to cascade subsystem noise requirements needed to achieve desired vehicle level performance. As a result, late and costly changes can be needed to make a given vehicle commercially acceptable for N&V performance prior to launch. This paper will cover the development of a two-step CAE method to predict modal characteristics and airborne noise sensitivities of large-diameter single piece aluminum propshafts fitted with different liner treatments. The first step is the use of a traditional CAE software to calculate prop surface
Jayaratne, Rajith R., Liu, Yu, Gehringer, Mark, Rayce, Jeff, Hill, Wallace
System Interactions Affecting NVH Performance of an Electric Vehicle Drivetrain2019-01-154506/05/2019
The paper will present an integrated approach to system NVH analysis, which gives an insight into the system response in an EV driveline due to electrical and mechanical excitations; namely rotor mechanical imbalance, electrical machine torque ripple, and stator radial force shapes. The paper will address the fact that, as part of a practical design exercise, different subsystems and components may achieve design maturity at different times. It is therefore important to understand to what extent various drivetrain components may be considered in isolation, and at what point it becomes necessary to consider the interactions present in the full system. The paper will compare predicted NVH performance of a representative EV traction motor when different boundary conditions are considered; for example, when considering the motor being bested in isolation as part of a typical test setup, and when included in a representative drivetrain. For each configuration, the response to mechanical and
Michon, Melanie, Holehouse, Robert, Shahaj, Annabel, Jafarali, Hisham, Janakiraman, Venkatakrishna
Tuning Aircraft Engines with OptiStruct Rotor Dynamics Simulation2019-01-136603/19/2019
It is typical in aircraft engine design to explore new configurations in a constant effort to achieve greater efficiency with respect to various considerations. An integral component of this process requires a complete and robust simulation of rotor dynamics. Tuning the design with results of rotor dynamics simulations can be made possible with a tool that has adequate modeling techniques to capture the physics associated with engine behavior under various operating conditions accurately.
Patnaik, Ujwal Kondavalasa, Saiki, Junji, Arcos, Illya
Plasma Generator Using Spiral ConductorsTBMG-3370302/01/2019
NASA's Langley Research Center has developed a patented SansEC sensor technology for use in many different areas, including tall structures and wind turbines. The SansEC technology is a proven wireless sensing platform capable of measuring the electrical impedance of physical matter in proximity to the sensor based on a change in its resonance response. The SansEC sensor also exhibits a unique characteristic to disperse the lightning strike current to help mitigate lightning damage. In a turbine blade application, an array of SansEC sensors will cover the surface area of the composite blade, providing both lightning mitigation and damage sensing. NASA Langley is seeking industrial partners/licensees to commercialize this technology. The research team at NASA Langley is available to assist with further development.
Modular, Multi-Mode-Propulsion, Unmanned Aerial ConceptTBMG-3362001/01/2019
NASA's Langley Research Center has developed an unmanned aerial vehicle concept for long-range, distributed aerial presence and delivery applications. This aircraft concept is capable of delivering multiple independent payloads over a range of more than 60 miles. The aircraft concept consists of two sub-aircraft: a “mother” vehicle and several “children” vehicles. The mother and children vehicles may operate both independently of one another and as a composite assembly. When not assembled, the mother and children vehicles rely on embedded ducted rotors for vertical lift and general propulsion.
Variable-Pitch Turbine BladesTBMG-3341012/01/2018
Gas turbine blades of conventional rotorcraft turboshaft engines are optimized to operate at nearly a fixed speed and a fixed incidence angle. If the operating condition of the engine changes, then the flow through the turbine may need to be guided to a more optimum direction.
Propeller Shaft Ends - Dual Rotation (Engine Supplied Bearing)AIR18B (Current)11/28/2018
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
Propeller Shaft Torque RatingsARP373C (Current)11/28/2018
E-25 General Standards for Aerospace and Propulsion Systems
Design, Development and Integration of a Wing-Morphing, Bimodal Unmanned Vehicle2018-01-196010/30/2018
This paper relates to the design and development of a multi-modal UAV capable of aerial flight and underwater propulsion. A novel hybrid propulsion system has been manufactured and tested. Consisting of folding blades, the propeller has been optimized for propulsion both in air and water. The critical water to air transition phase is achieved by an additional impulsive thruster powered by a C02 cartridge. To decrease the drag in underwater cruise and reduce the potential damage when the vehicle impacts the water, a morphing wing has been developed. This consists of foam-carbon fiber lay-up constructed wings in a variable sweep configuration. The actuation of the sweep is achieved by linear servos mounted on the sleeve shaped spar. An integrated prototype is constructed, using an unconventional, anhedral horizontal stabilizers to allow clearance for the morphing wing. Using a combination of data taken from wind tunnel testing, CFD simulation and analytic methods, models of the vehicles
Simpson, Mark, Guo, Dian
Lightweight, Wear Resistant, High Thermal Conductivity Metal Matrix Composite Brake Rotors2018-01-187910/05/2018
Aluminum (Al) - silicon carbide (SiC) metal matrix composite (MMC) brake rotors have been investigated for lightweight vehicular applications but have not widely been utilized due to issues with uniformity of distribution of SiC particulates, residual porosity, formation of undesirable phases such as aluminum carbide, and high temperatures incurred during braking that degrade the rotor’s integrity and performance. ATS-MER has overcome these issues with the development of a patented sandwich type structure with wear resistant thin Al-SiC MMC surface layers and a high thermal conductivity aluminum alloy core. Substantial dynamometer and vehicle testing has been performed by a major automobile company with excellent results, including much lower induced temperatures, 96.3 to 99.6% less particulate (dust) generation in comparable testing of cast iron rotors, and almost 10 times the number of maximum cycles possible during testing of cast iron discs. Thus, ATS-MER’s novel Al-SiC MMC brake
Bracamonte, Lori, Withers, James, Smith, Thomas
Brake System Design for Dedicated BEV Architectures2018-01-187010/05/2018
As fossil fuels dwindle and more electric vehicles enter the market, there is an opportunity to reevaluate the standard brake system. This paper will discuss and compare the differences in brake system sizing between a non-regenerative braking internal combustion engine vehicle and a dedicated battery electric vehicle with regenerative braking. It will use a model derived from component dynamometer testing and vehicle test data of a mid-size production vehicle. The model will be modified for the mass and regenerative braking capabilities of a battery electric vehicle. The contribution of regenerative braking energy will be analyzed and compared to show its impact on component sizing, thermal sizing, and lining life. The detailed design study will calculate the parameters for caliper, rotor design, actuation, etc., that are optimized for 100% regen enabled vehicles.
Shenberger, Michael J., Antanaitis, David
Thermodynamic Analysis of an Evaporative Inlet Air Cooled Combined Cycle for Marine Application2018-01-177709/10/2018
The integration of inlet air cooling to gas turbine based power utilities is a well accepted practice as this modification to the utility delivers superior utility performance. However, application of inlet-air cooling to drive turbines and specifically to marine mobility sector is rare in literature. Marine vessels are generally propelled by diesel engines, however large marine vessels specifically cruise ships and high speed naval vessels may have requirements of higher speeds and on-board power requirements which can fulfilled by gas turbine driving the propellers while on-board power needs can be met by steam turbine power generated from gas turbine exhaust heat. Such gas-steam combined cycles have the potential to become popular for high capacity marine vessels. The choice of gas turbine based combined cycle power plant for marine vessels in comparison to diesel engine powered vessel is also superior due to lower emission from the former. Higher ambient temperatures are known to
Mohapatra, Alok Kumar, S, Sanjay, Choudhary, Tushar, Kumari, Anupam, S, IRSHAD
BEARINGS, PLAIN, SELF-ALIGNING, SELF-LUBRICATING, 300 CPM (13 FPM) OSCILLATION, -65 TO +160 °F, LINERS LESS THAN .015 INCH THICKAS82819/1 (Current)08/23/2018
ACBG Plain Bearing Committee
Propeller Hub-Single RotationAS180B (Current)06/18/2018
E-25 General Standards for Aerospace and Propulsion Systems
Simulation and Comparative Analysis of Permanent Magnet Motor for Electric Vehicle with Different Rotor Structures2018-01-045604/03/2018
As one of the key technologies for EVs and HEVs, the design of their motors has been researched extensively, and some novel rotors of permanent magnet motor were proposed in order to improve torque capability, including average torque and torque ripple. Rotor structure selection of drive motor for various electric vehicles has been one of the key issues in matching of electric vehicle power system. Three motors are analyzed for providing visible insights to the contribution of different rotor structures to the torque characteristics, efficiency and extended speed range. First, an iterative comparative analysis of torque-speed characteristics with different flux linkage, d-axis inductance and rotor saliency ratio is performed for demonstrating the design principle. Then, the three motors are optimized by a genetic algorithm (GA) for further improving the torque characteristics. Third, a particular comparative analysis is performed among the flat one type, V type and triangle type 48/8
Yin, HongBin, Ma, Fangwu, Wei, Lulu, She, Shuo, Zhao, Ying, Gu, CanSong, Gao, Hui
Performance Optimization of Compressor Rotor Clutch Sub-assembly Using Electro- Magnetic Analysis2018-01-048404/03/2018
Rotor Clutch sub-assembly is one of the very important sub-assemblies (S/A) of an automotive compressor as it delivers the required torque/power to run the compressor. It mainly consists of rotor and bearing, stator, hub and armature. Rotor is rotated by engine pulley through belt drive system, while stator housing has got number of coils winded around stator slot. The hub sub-assembly is attached to the compressor shaft via spline arrangement and bolted across. When direct current (DC) is supplied to the terminal of the rotor, an electromagnetic field is generated which causes to attract the hub part towards rotor. Once the hub and rotor gets engaged each other, torque is transmitted to the compressor shaft which then helps to complete the suction and compression of refrigerant gas and thus making the vapor cycle run to produce adequate cooling in the air-conditioning (AC) system. Hence it is most important to ensure adequate and even distribution of electromagnetic field which is
Meena, Avadhesh, Sen, Somnath
An Online Fault Detection and Isolation Method for Permanent Magnet Synchronous Machine2018-01-045104/03/2018
An online fault detection and isolation (FDI) method for several common sensor faults and even demagnetization of PMSM is proposed by combining model-based and signal analysis technology. To begin with, the field reconstruction method (FRM) of PMSM is employed to obtain the flux residuals which are used as the criterion of fault detection. Then, the flux residuals are transformed by multi sequence harmonic synchronous rotating transformation and inputted into low pass filters (LPFs) in order to obtain the DC components. Last, offset and gain faults of the two phase current sensors, offset fault of the rotor angle sensor and permanent magnet (PM) demagnetization can be isolated by comparing the DC components and preset thresholds. The detection and isolation strategy of PMSM is validated by motor controller hardware in motor bench tests.
Zhong, Zaimin, Zhou, Shuihua, Chen, Xueping, Hu, Chengyu
Superalloy Surface Treatment for Improved Performance of Power TurbinesTBMG-2833002/01/2018
To produce power more efficiently and cleanly, the next generation of power turbines will have to operate at extreme temperatures and pressures. Currently, single-crystal, nickel-based superalloys are used in such extreme environments. MCrAlY coatings (where M = Co, Ni, or Co/Ni) are widely applied to first- and second-stage turbine blades and nozzle guide vanes, where they may be used as corrosion-resistant overlays or as bond coats for use with thermal barrier coatings.
Design and FE Analysis of a Permanent-Magnet Synchronizer Brake2017-01-245510/08/2017
This paper reports on the design of a synchronizer brake based on permanent magnets, capable of braking with an active zero-slip load. Eddy-current brakes are widely used in automation and transportation applications; however, their use is limited by the rotor speed. For low-speed and high-torque applications, designs based on permanent magnets are better suited. Zero-slip braking torque is increased by the use of permanent magnets but, consequently, so is the cogging torque. At first, the synchronizer brake was designed with 16 surface magnets on the rotor. However, in order to reduce the permanent magnet mass, the rotor was re-designed with half the number of surface magnets. This novel design helped lower cogging torque and fabrication costs. Simulation of the design, using the 3D transient with motion solver in commercial finite element software, showed promising results.
Chopra, Vikram
The Development of the Szorenyi Four-Chamber Rotary Engine2017-01-241310/08/2017
A four-chamber Otto cycle rotary engine, the Szorenyi Rotary Engine, has been invented and developed by the Rotary Engine Development Agency (REDA) in Melbourne, Australia. The engine concept has been awarded a U.S. Patent (Number 6,718,938 B2). A prototype engine has been constructed and a successful proof-of-concept engine test was achieved in 2008. The stator of the Szorenyi engine is a similar shape to a Wankel engine. However, the geometric shape of the engine rotor is a rhombus, which deforms as it rotates inside the contour of the mathematically defined stator. This geometry translates to a rotary engine with four combustion chambers. Each revolution of the crankshaft produces one revolution of the rotor; a complete engine cycle in each of the four chambers; and therefore four power strokes. In contrast, the Wankel engine produces one power stroke per crankshaft revolution. Additionally, the Wankel engine is rev limited due to the excessive crankshaft bending resulting from the
King, Peter
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