Browse Topic: Propellers and rotors

Items (795)
The propulsion system design of GM-Cadillac’s first electric vehicle Lyriq uses an optimized drive unit comprising interior permanent magnet (IPM) motors and silicon traction inverters. The main objective behind the drive unit design was to minimize energy losses and cost while maximizing hardware consolidation, range, performance, power density, and scalability. Two IPM motors with different length and number of stator turns are designed, while their rotor design and stator-conductor profile are kept the same. A high-speed rotor is designed to achieve higher power density. AC winding effect at higher speeds is mitigated by using a bar-conductor with much smaller cross section. The rotor surface has a special notch design to minimize acoustic noise, without use of rotor or stator skew. Also, the traction inverters in the Lyriq EV are engineered with a significant emphasis on being scalable and adaptable for various vehicle architectures while considering a broad range of requirements.
Momen, FaizulJensen, WilliamHe, SongChowdhury, MazharulZahid, AhsanForsyth, AlexanderAlam, KhorshedAnwar, MohammadKim, Young
The driving capability and charging performance of electric vehicles (EVs) are continuously improving, with high-performance EVs increasing the voltage platform from below 500V to 800V or even 900V. To accommodate existing low-voltage public charging stations, vehicles with high-voltage platforms typically incorporate boost chargers. However, these boost chargers incur additional costs, weight, and spatial requirements. Most mature solutions add a DC-DC boost converter, which results in lower charging power and higher costs. Some new methods leverage the power switching devices and motor inductance within the electric drive motor to form a boost circuit using a three-phase current in-phase control strategy for charging. This approach requires an external inductor to reduce charging current ripple. Another method avoids the use of an external inductor by employing a two-parallel-one-series topology to minimize current ripple; however, this reduces charging power and increases the risk
Yuan, BaochengMa, YongXie, XiLiu, ShaoweiGuan, TianyuGe, KaiZheng, LifuXu, Xu
This study presents a novel reinforcement learning (RL)-based control framework aimed at enhancing the safety and robustness of the quadcopter, with a specific focus on resilience to in-flight one propeller failure. This study addresses the critical need of a robust control strategy for maintaining a desired altitude for the quadcopter to save the hardware and the payload in physical applications. The proposed framework investigates two RL methodologies, dynamic programming (DP) and deep deterministic policy gradient (DDPG), to overcome the challenges posed by the rotor failure mechanism of the quadcopter. DP, a model-based approach, is leveraged for its convergence guarantees, despite high computational demands, whereas DDPG, a model-free technique, facilitates rapid computation but with constraints on solution duration. The research challenge arises from training RL algorithms on large dimension and action domains. With modifications to the existing DP and DDPG algorithms, the
Qureshi, Muzaffar HabibMaqsood, AdnanFayyaz ud Din, Adnan
This work deals with computational investigations of the component performances of Advanced Hexacopters under various maneuverings of the focused mission profiles. The Advanced Hexacopter is a kind of multirotor vehicle that contains more propellers and flexible arms, which makes this multirotor very maneuverable and aerodynamically efficient. This Hexacopter was designed specifically to execute multi-perspective applications along with enhanced payload-carrying capability. This Advanced Hexacopter contains a frame composed of modified arms equipped with coaxial rotors, which servo motors control. By providing specific and simple inputs to the microcontroller, the Hexacopter can autonomously undergo forward and backward maneuverings. The primary objective of this study is to analyze and compare different propeller configurational clearance sets that improve the maneuvering capability of this unmanned aerial vehicle (UAV), specifically emphasizing forward/backward and side maneuvering
Raja, VijayanandhNarayanan, SidharthElangovan, LogeshArumugam, LokeshSourirajan, LaxanaRaji, Arul PrakashKulandaiyappan, Naveen KumarGnanasekaran, Raj KumarMadasamy, Senthil Kumar
The integration of advanced horizontal axis turbines (HATs) into unmanned marine vehicles (UMVs) significantly enhances their operational efficiency by providing power sources. These vehicles, designed for diverse applications, require efficient power systems to operate autonomously over extended periods. The major disadvantages are limited battery life and energy storage capabilities that restrict the operational range and endurance of the UMVs. Utilizing HATs in UMVs provides a renewable energy source, reducing operational costs. This continuous power supply enhances mission capabilities and promotes energy independence, making them ideal for long-term missions. Thus, using Computational fluid dynamics (CFD) models, hydrodynamic and aerodynamic analyses were carried out. For the hydrodynamic scenario, a velocity of 10 m/s and for the aerodynamic case, 27.7778 m/s, were taken into consideration. It is concluded that the UMV with Stepped HAT modification can be effectively employed for
Gunasekaran, Durga DeviKannan, HaridharanSourirajan, LaxanaVinayagam, GopinathGnanasekaran, Raj KumarKulandaiyappan, Naveen KumarStanislaus Arputharaj, BeenaL, NatrayanRaja, Vijayanandh
This article explores the utilization of simple-cubic, diamond, octet-truss, and X-type lattice structures for low-pressure turbine blades in engine turbines to enhance natural frequency and decrease overall engine weight while maintaining structural integrity. The research method involves analyzing polylactic acid (PLA) hollow T106C blades with fully infilled and 50–80 location-based lattice arrangements. The study modifies the strut thickness of lattice structures using both constant and variable-based approaches and applies a generalized formula based on relative density to evaluate how changes in lattice thickness and arrangements influence natural frequencies. Furthermore, the investigation extends to multi-lattice configurations, introducing a parameter 𝑘 to signify the transition between different lattices. The modified blades were 3D printed using PLA and tested for natural frequencies through modal testing. The results demonstrate that location-based 50–80 exponential-based
Reewarabundith, Siwachai
This work focuses on the design and multi-parametric analysis of a designed propeller for a Pentacopter unmanned aerial vehicle (UAV). The basic and secondary design inputs, along with performance data like propeller diameter, pitch angle, chord length, and lift coefficient, are established using a standard analytical method. Approximately ten distinct airfoils, specifically NACA 2412, NACA 4109, NACA 4312, NACA 4409, NACA 4415, NACA 5317, NACA 6409, NACA 6412, NACA 23024, and NACA 25012, are evaluated over 13 Reynolds Numbers with the angle of attacks (AOA) of 20, varying from -5 to 15 degrees, for the purpose of detailed propeller design. The lift and drag coefficient values for ten distinct airfoils, utilizing a Reynolds number of 13 and 20 angles of attack, are obtained from the XFOIL software. Three sophisticated airfoils are selected from a pool of ten based on their high Lift-to-Drag (L/D) ratio performance. The selected airfoils with a high L/D ratio are NACA 6409, NACA 4109
Veeraperumal Senthil Nathan, Janani PriyadharshiniArumugam, ManikandanRajendran, MahendranSolaiappan, Senthil KumarKulandaiyappan, Naveen KumarMadasamy, Senthil KumarStanislaus Arputharaj, BeenaL, NatrayanRaja, Vijayanandh
Exploration vehicles on Titan are to be developed with considerations on the atmosphere present, especially the abundance of Nitrogen. This study focuses on identification of optimum materials for the propellers supporting an airship specifically created for Titan exploration. The base airship is designed to accommodate the coaxial propeller. The base of this airship is to be developed with four weather stations for collection of data samples. The stations are installed on inflatable platforms and have storage devices for recording and transmitting data collected by the aerobot. The airship will operate in Titan's atmosphere and atmospheric conditions, focusing on its design and computational analysis of structural effects and fluid dynamics. The Titan aerobot is built with a co-axial 4-blade propeller, horizontal and vertical fins, and a reaction wheel for yaw maneuvers. The co-axial propulsive system is capable of overcoming drag during steady level flight in the Titan atmosphere
Baskar, SundharVinayagam, GopinathPisharam, Akhila AjithGnanasekaran, Raj KumarRaji, Arul PrakashStanislaus Arputharaj, BeenaL, NatrayanGanesan, BalajiRaja, Vijayanandh
This paper designs a low-budget yokeless and segmented armature (YASA) axial flux permanent magnet synchronous machine, which replaces some of the PMs attached to the rotor with silicon steel plates. For the purpose of checking the effectiveness of the proposed machine, the equivalent magnetic circuits of the typical and proposed YASA machines are first compared and analyzed, and then the models of the two machines are constructed and simulated. The results prove that the proposed YASA machine significantly reduces the quantity of permanent magnets compared to the typical machine. In addition, the thickness of the machine rotor disc has been reduced by optimizing the machine, which both enhances the power density and reduces the volume of the machine. Finally, the rotor-stator magnetic pulling force of the machine is simulated and analyzed, and the results prove that the proposed machine can operate stably.
Li, TaoWang, BitanDiao, ChengwuZhao, Wenliang
Monitoring the rotor temperature of drive machines is crucial for the safety and performance of electric vehicles. However, due to the complex operating conditions of electric vehicles, the thermal parameters of vehicular induction machines (IMs) vary significantly and are difficult to identify accurately. This article first establishes a concise but effective thermal network for IMs and analyzes the influencing factors of thermal parameters. Then, a parameter identification network (PIN) with multiple parallel branches is constructed to learn the mapping relationship between electromechanical variables and thermal parameters. Afterward, temperature datasets for network training are built through bench testing. Finally, the effectiveness of identified parameters for rotor temperature estimation application is verified, demonstrating improved interpretability, generalization ability, and accuracy compared to an end-to-end neural network.
Jiang, ShangHu, Zhishuo
The inductance parameter is important for the flux regulation performance of the hybrid excitation motor, and the axial structure leads to the change in the inductance parameter of the axial-radial hybrid excitation motor (ARHEM). To clarify the inductance characteristic of the ARHEM with different winding construction and the mutual coupling effect between the axial excitation and permanent magnet excitation on the inductance. Firstly, the structure of the ARHEM is presented. Secondly, the self and mutual inductance characteristics of ARHEM are analyzed using the winding function method. Then, the influence of the axial excitation structure on the armature reaction field and saliency ratio of ARHEM. On this basis, the mechanism of the mutual coupling, between the axial excitation and permanent magnet field under different excitation currents on the main air gap magnetic field, and the inductance of ARHEM with fractional slot are revealed.
Fu, DongXueZhao, HeweiWu, QiminYuan, ChunweiWang, DongQiu, Hongbo
In this paper, a comprehensive analysis of NVH in electric powertrains due to electromagnetic sources is presented. The spatial harmonics model of the traction motor, which is dependent on the motor design structure, rotor poles, stator teeth, and slots, is used for the analysis of the electromagnetic forces from the motor in the electric powertrain. The time harmonics model of the injected current of the motor dependent on the drive electrical circuit and control strategy is also considered for the electromagnetic force calculation. A complete workflow of this electromagnetic NVH analysis for electric powertrain covering the spatial harmonics and time harmonics model is presented. The spatial harmonics model result is presented as flux linkage with respect to dq-axes current and rotor position. The time harmonics are also presented by the injected current of the motor. In addition, a set of operating points on the torque-speed boundary of the traction motor is selected and results are
Joshi, NakulKumar, VinitTsoulfaidis, AntoniosHuang, ZhenhuaSchmaedicke, MarcelFialek, GregoryZhang, DapuWimmer, Joe
Rotor and Stator are the key constituents of an electric motor that are made of several laminates punched from a sheet metal and stacked together. The rotor stack is inserted with magnets at the punched-out pockets and is assembled with a shaft via press fitting. Rotor assembly being the rotating part of an E-Motor is subjected to centrifugal loads due to masses of magnets, lamination stack and shaft rotating at high speeds, temperatures and assembling loads because of which rotor laminates experience failures as the high strains develop in the regions on the laminate that support magnets. Typically, these high strain locations are the sections of the magnet pockets one on the outer diameter of the laminate and the other at the sections between the magnet pockets. Traditionally, these high strains are addressed by increasing the area of these sections, but this has a detrimental effect on the electromagnetic performance. Instead of increasing the area of these sections, the proposed
Pawde, DeepakSrimathkandala, MaithiliGalande, Pandurang
This document provides the specifications of horizontal hard-bearing balancing machines, which make such machines suitable for gas turbine rotor balancing.
EG-1A Balancing Committee
Brake squeal is a phenomenon caused by various factors such as stiffness of brake components, mode coupling, friction coefficient, friction force variation, pressure, temperature and humidity. FEA simulation is effective at predicting and investigating the cause of brake squeal, and is widely used. However, in many FEA simulations, models of brake lining are mostly a brand-new shaper, so that the change of pressure distribution or pad shape, which can occur due to the lining wear, are not taken account. In this research, brake squeal analysis was conducted with consideration of lining wear, applying Fortran codes for Abaqus user subroutine. The brake assembly model for the analysis is created by using a 3D scanner and has a close shape to the real one. The wear patterns calculated by the analysis are similar to those of brake pads after a noise test. The complex eigenvalue analysis shows two unstable modes at the frequency of squeal occurred in the noise test. One is out-of-plane
Ikegami, TokunosukeMillsap, TomYamaguchi, Yoshiyuki
This article aims to conduct a comprehensive performance analysis of various propeller configurations and motors for uncrewed aerial vehicles. The experimental method is used for this study through the performance analysis of the motors and propellers at various conditions. In this study, the test rig has been manufactured specially to test the propeller and motor configuration as per the standard to obtain the thrust at various supplied voltage. This study proved that the increase in the size of propeller leads to increase in the thrust, as well as it can be used for specific applications of the drone like racing drone. It reveals that the maximum diameter of a propeller is 14 inches, which produces the thrust in the range of 2400 g to 361 g depending on motor capacity compared to the other size of the propellers. The novelty of the work is to analyze the performance of propellers and motors for optimization and application of drones through experimental methods. This method can be
Ajay Vishwath, N.C.Balaji, K.Vaishampayan, VibhavPatil, DeepMehta, ParshvaDonde, Gaurangi
There are examples in aerodynamics that take advantage of electric-to-aerodynamic analogies, like the law of Biot–Savart, which is used in aerodynamic theory to calculate the velocity induced by a vortex line. This article introduces an electric-to-aerodynamic analogy that models the lift, drag, and thrust of an airplane, a helicopter, a propeller, and a flapping bird. This model is intended to complement the recently published aerodynamic equation of state for lift, drag, and thrust of an engineered or a biological flyer by means of an analogy between this equation and Ohm’s law. This model, as well as the aerodynamic equation of state, are both intended to include the familiar and time-proven parameters of pressure, work, and energy, analytical tools that are ubiquitous in all fields of science but absent in an aerodynamicists’ day-to-day tasks. Illustrated by various examples, this modeling approach, as treated in this article, is limited to subsonic flight.
Burgers, Phillip
With the automotive industry’s increasing focus on electromobility and the growing share of electric cars, new challenges are arising for the development of electric motors. The requirements for torque and power of traction motors are constantly growing, while installation space, costs and weight are increasingly becoming limiting factors. Moreover, there is an inherent conflict in the design between power density and efficiency of an electric motor. Thus, a main focus in today’s development lies on space-saving and yet effective and innovative cooling systems. This paper presents an approach for a multi-physical optimization that combines the domains of electromagnetics and thermodynamics. Based on a reference machine, this simulative study examins a total of nine different stator cooling concepts varying the cooling duct positions and end-winding cooling concepts. To ensure the highest possible comparability, the rotor geometry as well as the overall dimensions in terms of outer
Reinecke, MikeKarayel, Akifvon Schöning, HendrikSchaefer, UweMoullion, MatthiasFaessler, VictorLehmann, Robert
The rotor and stator of electric motors consist of multiple materials, of which steel forms the majority of mass and volume. Steel in electric motors is commonly in the form of thin sheets (laminations), stacked along the axis of the rotor. The structural integrity of such a stack can be ensured using bolting, welding or bonding of the laminations. Predictive mechanical finite element simulations of these laminated stacks can become computationally intense because the steel sheets are thin, and the motor often contains hundreds of them. If the laminations are modelled individually, the size of the elements is very small compared to the overall dimensions and the interface between the laminations need to be modelled as well. In this paper, we present an alternate method of modelling this laminated stack as a single solid body using homogeneous and orthotropic material property, instead of representing each lamination. This provides realistic predictions of mechanical performance, while
Goel, AshishP, PraveenSharma, HirenFaggioli, Thiago
The modern luxurious electric vehicle (EV) demands high torque and high-speed requirements with increased range. Fulfilling these requirements gives rise to the need for increased efficiency and power density of the motors in the Electric Drive Unit (EDU). Internal Permanent Magnet (IPM) motor is one of the best suited options in such scenarios because of its primary advantages of higher efficiency and precise control over torque and speed. In the IPM motor, permanent magnets are mounted within the rotor body to produce a resultant rotating magnetic field with the 3-phase AC current supply in the stator. IPM configuration provides structural integrity and high dynamic performance as the magnets are inserted within the rotor body. Adhesive glue is used to install the magnets within the laminated stack of rotor. High rotational speed of rotor introduces centrifugal loading on the magnets which can result in multiple failure modes such as the debonding of the magnet, and high radial
Karmakar, NilankanP, PraveenGoel, Ashish
In electric vehicle applications, the majority of the traction motors can be categorized as Permanent Magnet (PM) motors due to their outstanding performance. As indicated in the name, there are strong permanent magnets used inside the rotor of the motor, which interacts with the stator and causes strong magnetic pulling force during the assembly process. How to estimate this magnetic pulling force can be critical for manufacturing safety and efficiency. In this paper, a full 3D magnetostatic model has been proposed to calculate the baseline force using a dummy non-slotted cylinder stator and a simplified rotor for less meshing elements. Then, the full 360 deg model is simplified to a half-pole model based on motor symmetry to save the simulation time from 2 days to 2 hours. A rotor position sweep was conducted to find the maximum pulling force position. The result shows that the max pulling force happens when the rotor is 1% overlapping with the stator core. The impact of asymmetric
Gong, ChengChang, LeHe, SongZhang, PengMuir, Michael
Wound rotor synchronous machines (WRSM) without rare-earth magnets are becoming more popular for traction applications, but their potential in drive performance has not yet been fully explored. This paper presents a Pulse Width Modulation (PWM) scheme optimization procedure to minimize motor and inverter losses. It leverages different PWM schemes with different PWM switching strategies and switching frequencies. First, a generic PWM-induced motor loss calculation tool developed by BorgWarner is introduced. This tool iteratively calculates motor losses with PWM inputs across the entire operating map, significantly improving motor loss prediction accuracy. The inverter losses are then calculated analytically using motor and wide-bandgap (WBG) switching device characteristics. By quantifying these various scenarios, the optimal PWM scheme for achieving the best system efficiency across the entire operating map is obtained. The PWM-induced motor loss characteristics, the system loss
Ma, CongTyckowski, Joseph
This article presents a method for improving electric motor noise and vibration analysis based on rotor load. The method first obtains two key parameters, namely the characteristics of the stator and rotor core material and the connection stiffness between the rotor skewed poles, through modal testing and simulation calibration of the stator and rotor. Subsequently, the electromagnetic simulation is used to calculate the torque fluctuation of each segment of the rotor skewed poles, which is used as input load for the structural simulation. The vibration of the suspension point and the radiation noise of the transmission housing are then calculated under the action of torque fluctuation. The study highlights the significant contribution of the rotor torsional mode to noise and vibration. Finally, by improving the torsional stiffness of the rotor and the distribution of skewed poles, the noise and vibration problems caused by torsional mode can be significantly improved, leading to
Zhang, JingwenGeng, ZhirongLi, QiangLi, Shuangchi
Additive manufacturing (AM) is currently the most sought-after production process for any complex shaped geometries commonly encountered in Aerospace Industries. Although, several technologies of AM do exits, the most popular one is the Direct Metal Laser Sintering (DMLS) owing to its high versatility in terms of precision of geometries of components and guarantee of highest levels of reduction in production time. Further, metallic component of any complex shape such as Gas Turbine Blades can also be developed by this technique. In the light of the above, the present work focuses on development of iron silicon carbide (Fe-SiC) complex part for ball screw assembly using DMLS technique. The optimized process parameters, hardness and wear resistance of the developed iron-SiC composite will be reported. Further, since the material chosen is a metallic composite one, the effect of SiC on the thermal stresses generated during the DMLS processing of Fe-SiC composite will also be discussed. A
Chinnakurli Suryanarayana, RameshCheekur Krishnamurthy, SrinivasaH, AdarshaMukunda, Sandeep
Electric motors constitute a critical component of an electric vehicle powertrain. An improved motor design can help improve the overall performance of the drivetrain of an electric vehicle making it more compact and power dense. In this article, the electromagnetic torque output of a double V-shaped traction IPMSM is maximized by geometry optimization, while considering overall material cost minimization as the second objective. A robust and flexible parametric model of the IPMSM is developed in ANSYS Maxwell 2D. Various parameters are defined in the rotor and stator geometries to perform an effective multi-objective parametric design optimization. Advanced sensitivity analysis, surrogate modeling, and optimization capabilities of ANSYS optiSlang software are leveraged in the optimization. Furthermore, a demagnetization analysis is performed to evaluate the robustness of the optimized design. At high-speed operation, a rotor core is usually subject to higher deformation due to the
Agrawal, AniruddhaSahu, AshishJuarez-Leon, Francisco AlejandroHaddad, Reemon Z.Al-Ani, DhafarBilgin, Berker
CFM International Cincinnati, OH 513-552-3272
Brake squeal is a common phenomenon across all types of vehicles. It becomes prominent in the absence of other noise sources, as in the case of electric vehicles. Earlier simulation attempts date back to late nineties and early 2000s. Identification of unstable modes of the coupled system of brake rotor and pads, and occasionally some caliper components, was the primary goal. Simulating the rotation of the rotor along with squeezing of the pads was attempted in a multi-body dynamics tools with flexible representation of rotor and pads. Though this gave some insights into the dynamics of stopping mechanism, squeal required capturing the nonlinearities of the contact in a more rigorous sense. Also, efforts were made to capture noise from vibrations using boundary- and finite- element methods [1]. In this attempt at digitalizing a brake dynamometer, the author used a nonlinear implicit solver to mimic the dynamics and transient vibro-acoustic solver to convert transient vibrations to
Kappagantu, Ramana
During validation of a new brake lining on a light duty truck application, the brake rotor exhibited high lateral runout on the friction surfaces. As the engineering team investigated the issue more carefully, they noticed the rotor lateral runout was also changing from revolution to revolution. The team ran testing on multiple light pickup vehicles and found differences in the amount of rotor runout variation. The rotor lateral runout and runout variation can cause vibration and pulsation of the passenger seat and the steering wheel. To identify the root cause of the high level of rotor lateral runout and runout variation, measurement data was collected and analyzed from the vehicle level test. During further analysis, some of the runout variation corresponded to a wheel bearing internal frequency. The bearing internal geometry was studied to confirm what factors affected the runout variation. The team also conducted testing to see how the mating components may have affected the wheel
Hwang, HyungdooKuehl, PaulSutherlin, RobertGrubaugh, Kelly
As an important part of the Roots hydrogen circulation pump, the rotor system has a significant impact on the dynamic characteristics of the Roots hydrogen circulation pump. In this paper, the finite element model of the rotor system of the Roots hydrogen circulation pump in the fuel cell hydrogen supply system was built, and the dynamic characteristics of the coupled dual-rotor system were studied. Through the modal analysis of the rotor system, the first six-order natural modes and natural frequencies of the uncoupled single-rotor system and the coupled dual-rotor system were obtained. The harmonic response characteristics of the rotor system were analyzed on the basis of the modal analysis, and the harmonic response characteristic curves of the gear and the edge of the impeller were obtained. The results show that the vibration deformation of the shaft end and the rotor impeller is relatively large, and the vibration response amplitude of the rotor system is the largest when the
Lin, MengzhuGao, Yuan
The purpose of this SAE Aerospace Information Report (AIR) is to provide guidance for aircraft engine and propeller systems (hereafter referred to as propulsion systems) certification for cybersecurity. Compliance for cybersecurity requires that the engine control, propeller control, monitoring system, and all auxiliary equipment systems and networks associated with the propulsion system (such as nacelle systems, overspeed governors, and thrust reversers) be protected from intentional unauthorized electronic interactions (IUEI) that may result in an adverse effect on the safety of the propulsion system or the airplane. This involves identification of security risks, their mitigation, verification of protections, and their maintenance in service. This document is intended to serve as suitable guidance for propulsion system manufacturers and applicants for propulsion system type certification. It is also intended to provide guidance for subsequent propulsion system integration into
E-36 Electronic Engine Controls Committee
Electrification is seen as having an important role to play in the fossil-free aviation of tomorrow. But the more energy-efficient an electric aircraft is, the noisier its propellers get. Now, researchers at Chalmers University of Technology have developed a propeller design optimization method that paves the way for quiet, efficient electric aviation.
Since the introduction of ice crystal icing certification requirements [1], icing facilities have played an important role in demonstrating compliance of aircraft air data probes, engine probes, and increasingly, of turbine engines. Most sea level engine icing facilities use the freezing-out of a water spray to simulate ice crystal icing conditions encountered at altitude by an aircraft in flight. However, there are notable differences in the ice particles created by freeze-out versus those observed at altitude [2, 3, 4]. Freeze-out crystals are generally spherical as compared to altitude crystals which have variable crystalline shapes. Additionally, freeze-out particles may not completely freeze in their centres, creating a combination of super-cooled liquid and ice impacting engine hardware. An alternative method for generating ice crystals in a test facility is the grinding of ice blocks or cubes to create irregular shaped crystals. These grind-out particles have a different
Neuteboom, MartinFleurent-Wilson, EricChalmers, Jennifer
Aircraft icing is the phenomenon that forms an ice layer on the solid surface by impingement of supercooled water droplets in the atmosphere. In icing on rotor blades, ice is shed from the blade surface by centrifugal force as the accumulated ice grows. The ice shedding on rotor blades is a dangerous phenomenon, but the physical mechanism and properties are unclear, and most simulations have not considered it. Therefore, it’s necessary to establish an ice shedding model for icing simulations. In this study, we proposed an ice shedding model in which the condition for ice shedding is that the centrifugal force exceeds both the adhesion and tensile forces. Centrifugal force exceeding adhesion force expresses adhesion failure, while centrifugal force exceeding tensile force expresses cohesion failure. We also proposed functions of temperature and medium volume diameter (MVD) as adhesion strength and tensile strength for ice shedding judgment. Numerical simulations were performed to
Baba, TatsuyaFukudome, KojiYamamoto, MakotoMizuno, TakuyaSuzuki, Masaya
Urban air mobility (UAM) is a fast-growing industry that utilizes electric vertical take-off and landing (eVTOL) technologies to operate in densely populated urban areas with limited space. However, atmospheric icing serves as a limitation to its operational envelope as in-flight icing can happen all year round anywhere around the globe. Since icing in smaller aviation systems is still an emerging topic, there is a necessity to study icing of eVTOL rotors specifically. Two rotor geometries were chosen for this study. A small 15-inch rotor was selected to illustrate a multirotor UAV drone, while a large 80-inch rotor was chosen to represent a UAM passenger aircraft. The ice accretion experiments were conducted in an icing wind tunnel on the small 15-inch rotor. The icing simulations were performed using FENSAP-ICE. The ice accretion simulations of the 15-inch rotor sections at –5 °C show a large, rather streamlined ice shape instead of the expected glaze ice characteristics. At –15 °C
Heramarwan, HenidyaMüller, NicolasHann, RichardLutz, Thorsten
Ice accretion on helicopter rotor blades when flying through supercooled droplet clouds can severely affect aerodynamic properties and pose a significant threat to flight safety. In the design phase, manufacturers commonly use 2D or quasi-3D simulations to predict potential ice accretion, which are more economical than fully 3D approaches. However, these methods frequently encounter accuracy issues when predicting the precise amount of ice accretion because the 3D flow field significantly influences droplet trajectories and, as a result, impingement and accreted mass. For this study the Eulerian particle solver of the icing software DICEPS was upgraded from 2D to 3D using second-order schemes, ensuring numerical stability on unstructured mesh configurations. Validation of the 3D modifications was performed by comparing numerical results of the collection efficiency on a sphere with experimental data. Droplet trajectory calculations were then conducted on a NACA0012 rotor in hover
Buchen, PhilippSotomayor-Zakharov, DenisKnop, Inken
In-flight atmospheric icing is a severe hazard for propeller-driven unmanned aerial vehicles (UAVs) that can lead to issues ranging from reduced flight performance to unacceptable loss of lift and control. To address this challenge, a physics-based first principles model of an electric UAV propulsion system is developed and identified in varying icing conditions. Specifically, a brushless direct current motor (BLDC) based propeller system, typical for UAVs with a wing span of 1-3 meters, is tested in an icing wind tunnel with three accreted ice shapes of increasing size. The results are analyzed to identify the dynamics of the electrical, mechanical, and aerodynamic subsystems of the propulsion system. Moreover, the parameters of the identified models are presented, making it possible to analyze their sensitivity to ice accretion on the propeller blades. The experiment data analysis shows that the propeller power efficiency is highly sensitive to icing, with a 40% reduction in thrust
Løw-Hansen, BogdanMüller, Nicolas C.Coates, Erlend M.Johansen, Tor ArneHann, Richard
In-flight atmospheric icing is a significant threat to the use of unmanned aerial vehicles (UAVs) in adverse weather. The propeller of the UAV is especially sensitive to icing conditions, as it accumulates ice at a faster rate than the wings of the UAVs. Ice protection systems can be developed to counteract the danger of icing on the propeller of UAVs. In this study, the influence of different meteorological conditions on a propeller of a UAV is analyzed for a UAV with a wingspan of a few meters. The ice accretion and the performance degradation and the required anti-icing heat fluxes have been calculated using numerical methods with ANSYS FENSAP-ICE. This analysis has been used to evaluate the critical conditions for the operation of a UAV in icing conditions and the design of a thermal IPS system for a propeller. The highest ice mass has been found at a temperature of −10 °C and an MVD of 20 μm in intermittent maximum icing conditions. The performance degradation has been the highest
Müller, Nicolas CarloHann, Richard
Modifications have been implemented in the GlennICE software to accommodate a non-inertial reference frame. GlennICE accepts a flow solution from an external flow solver. It then introduces particles and tracks them through the flow field in a Lagrangian manner. Centrifugal and Coriolis terms were added to the GlennICE software to account for relative frame simulations. The objective of the present paper is twofold. First, to check that the new terms are implemented correctly and that the code still behaves as expected with respect to convergence. And second, to provide some initial insight into an upcoming propeller experiment in the NASA Icing Research Tunnel. The paper presents a description of the code modifications. In addition, results are presented for two operating conditions, and three particle sizes. Each case was simulated with four different grid densities to assess grid dependence.
Rigby, Davidvon Hardenberg, Paul
This paper is focused on the numerical analysis of the impingement and water catch rate of snow particles on the engine air intake of the Next Generation Civil Tilt Rotor (NGCTR). This NGCTR is developed by Leonardo Helicopters. The collection efficiency and water catch rate for the intake geometry are obtained for the test cases that have been defined for the relevant snow conditions. These conditions are related to the flight envelope of the NGCTR, existing EASA/FAA certification specifications, and the snow characterization. The analyses have been performed for the baseline air intake geometry. A range of particle diameters has been simulated with a particle density equal to the density of ice and with a particle drag relation that disregards the particle shape. Based on the results for the water catch rate on the basic nacelle configuration in snow conditions it is concluded that the ‘cheeks’ of the duct are more susceptible to impingement of larger snow crystals (>75 μm), whereas
Kool, NinaVan der Weide, EdwinSpek, Ferdinandvan der Ven, Harmenvan 't Hoff, Stefan
The development and calibration of a new facility to test medium size rotors for Remotely Piloted Aircraft Systems (RPAS) under in-flight icing conditions is described. This facility has made use of a 3 m x 6 m cold room available at the NRC which includes a spray system to provide the icing cloud as well as a dedicated rotor stand assembly that incorporates a load cell and dynamometer. Calibration data of the spray drop sizes and liquid water content are provided and compared to conditions of the natural environment as detailed in icing regulations for transport category airplanes, i.e., CFR 14 Part 25 Appendix C and O. Data to examine the sensitivity of rotor performance, under a constant liquid water content to various droplet sizes are provided for a medium sized rotor. Tests have also been performed that examine the ability of the rotor to maintain predefined thrust, torque and power performance throughout an icing encounter of fixed duration. For the purposes of this study, the
Orchard, David
In this research, the performance of two commercially available icephobic coatings is evaluated on an 81% scaled-down version of the Bell Flight APT 70 drone propeller. Tests are performed in an icing wind tunnel (IWT) under selected severe icing conditions to test the ice protection capability of coatings against both glaze and rime ice. Two different coating formulations are used, one is a polydimethylsiloxane (PDMS) acetoxy terminated coating, the other an epoxy-silicone. The coatings were briefly characterized in terms of their surface roughness, water contact angle and ice adhesion reduction factor compared to aluminum using the centrifugal adhesion test (CAT). Blade sets were prepared for both coatings and a third uncoated set was tested for reference purposes. Tests in the IWT were performed to simulate a true airspeed of 35 m/s and a constant propeller rotational speed of 5 500 RPM. Two conditions of liquid water content (LWC) and droplet median volumetric diameter (MVD) were
Harvey, DerekVilleneuve, EricVolat, ChristopheBeland, MathieuLapalme, Maxime
This SAE Aerospace Recommended Practice will serve as a practical resource that offers guidance to both the machine operator and process engineer for isolating the source(s) of non-repeatability in measured unbalance data. The content of this standard addresses: Machine capability to achieve the specified unbalance tolerances and repeat within those tolerances. Tooling capability to repeat within the specified unbalance tolerances. Rotor characteristics that may preclude repeating within the required unbalance tolerances.
EG-1A Balancing Committee
This SAE Aerospace Information Report (AIR) defines the helicopter bleed air requirements which may be obtained through compressor extraction and is intended as a guide to engine designers.
S-12 Powered Lift Propulsion Committee
Community noise at vertiports is one of the most important questions related to upcoming urban air mobility (UAM) operations. While fixed-wing and/or fixed-rotor aircraft can mainly be treated by their changing operational parameters, such as rotor or propeller rpm, tilt-wing or tilt-engine configurations are more difficult to simulate because of their constantly changing noise emission and spatial radiation characteristics. The work presented in this paper is providing an overview of the noise situation at a virtual vertiport which is being approached and departed by a tilt-wing air-taxi in different ways. Several different departure procedures are simulated with the same generic air-taxi. For the noise emission semi-empiric methods were used. During the air-taxi’s descent and climb, different tilt configurations are included, mainly defined by the time dependent engine’s tilt-angle, but also related to different approach paths. Each approach or departure procedure is generating
Bauer, Michael
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 mechanics
Burgers, Phillip
In rotor engineering, one must achieve a rotor design incorporating a well-controlled state of unbalance. A reduced nominal rotor unbalance assures achieving permissible vibration responses during measurement. Geometric feature controls associated with manufacturing drawings are root causes of vibratory measurements during engine testing. Difficulties arise during component design using software that fails to account for the presence of unbalance, or the ability to achieve a balanced state for each rotor design. Manufacturing procedures ensure that serial production articles are within tolerance limits established by the manufacturing drawings. This process is intended to ensure unbalance contributions estimated during the design phase will permit vibration limits to be met during final acceptance test. Performance of a rigid rotor under test cell conditions is dependent upon effective control of runout and eccentricity between mating components. Establishment of these tolerances must
Buschbeck, A.Hill, C.El-Sawaf, T.
This article presents one approach to the mathematical modeling and analysis of a turbojet engine with the primary goal of defining the transfer function and simulation model. Extensive research on turbojet engine dynamic parameters in the time and frequency domains has been presented. The turbojet engine transfer function was defined based on the operation characteristics and experimental test data, which included fuel flow, turbine rotation speed, and exhaust gas temperature. For the turbojet engine, where the turbine rotation speed was defined as a controlled parameter, fuel flow was used as a control parameter. The total gain of the control object and the time constant parameters were determined as nonlinear functions, which primarily depend on turbojet engine mechanical characteristics and thermodynamic processes. Using the Simulink digital simulation platform, a dynamic turbojet engine simulation was performed. In limited operational conditions on the ground test cell, turbojet
Novakovic, Neno
Items per page:
1 – 50 of 795