eVTOL (Electric Vertical Take-Off and Landing) & UAM (Urban Air Mobility): FEA & CFD Based Simulation for Ground Vibration Testing (GVT), Airworthiness Certification, Aerodynamics, Aeroacoustics and Crashworthiness
The VTOL, eVTOL and UAM market is constantly changing and evolving, so maintaining a competitive edge both within the industry and supporting mission effectiveness requires significant research and development activities. Enteknograte offers the industry’s most complete simulation solution for vertical-takeoff-and-landing (VTOL) aircraft. Our research and development procedure has required a blend of qualities such as ambition, drive and commitment as well as more tangible assets such as specialist engineering skills, rapid development through simulation techniques, supreme electronics expertise and a ruthless quest for performance and reliability.
The level of partnership and support for Developing a leading edge VTOL, eVTOL and UAM system FEA and CFD simulations that our customers get is just as important to us. We are investing time and resources to ensure customers receive support and service that is of the same, highest possible standards as the reliability and performance.
Increase efficiency, reduce noise, costs, and time-to-market of rotorcraft and eVTOL vehicles with an integrated design, simulation and optimization process
- Leverage an integrated design and analysis process to develop preliminary VTOL aircraft designs that maximize propulsion efficiency in hover, maximize aerodynamic efficiency in cruise and minimize noise over the entire flight envelope.
- Use high-fidelity fluid dynamics simulation in an optimization loop to maximize propulsion efficiency and minimize noise in hover.
- Reduce blade-vortex interaction and loads acting on the control surfaces during conversion.
- Design for low-noise manuevers.
- Analyze the acoustic impact in a urban environment during take-off and landing.
- Reduce product development costs and reduce time-to-market using digital simulations to predict performance early in the design cycle rather than physical tests in the late stages of development
Vibroacoustics performance assessment of aircraft panels in low, mid and high frequency regimes
A true VTOL system design has complex challenges, particularly designing for a high thrust for hover while also reducing drag for cruise. In simple terms, you are designing a helicopter and forward-flying aircraft in the same product.
Vibroacoustic (VA) characteristics, namely sound transmission loss, overall sound pressure levels of aircraft panels made up of different materials such as aluminum, composites and fiber metal laminates can be analyzed with optimization approach for aircraft panels.
The investigation involves modeling of aircraft panels using finite element method (FEM) for low frequency, Boundary Element Method (BEM) for mid-frequency and statistical energy analysis (SEA) in high-frequency bands. To obtain the VA characteristics of the panels, twin chambers, namely source and receiver are numerically modeled, and the panels are placed in between them. This numerical study helps in understanding the VA behavior of aircraft materials and also minimizes the cost and time involved in conducting experiments.
eVTOLs and UAM Crashworthiness certification
Occupant safety is an integral part of the design, development, and operation of urban air mobility (UAM) systems. Emergency landing conditions design requirements specified in (Code of Federal Regulations) (Certification standard ) may not provide the level of safety for eVTOL vehicles.
The successful implementation of the UAM market will require emergency landing concepts that address real-world safety expectations. An integrated safety development process will help you maintain survivable volume, minimize deceleration loads to occupants, maintain egress paths and evaluate retention items of mass.
Enteknograte engineers optimize eVTOL aircraft crashworthiness from the conceptual design stage using most advanced computational tools.
How multibody models and optimization tools can be used to define integrated safety concepts for:
- Landing gear and airframe crashworthiness
- High-energy absorbing seats, and advanced restraints
- Cabin subfloor structures
- Energy-absorbing landing and take-off sites
Airworthiness certification with efficient aircraft ground vibration: Ground Vibration Testing (GVT)
Ground vibration testing (GVT) is a major milestone in the FAA aircraft certification process and EASA.The main purpose of the test is to obtain experimental vibration data for the entire aircraft structure so you can validate and improve its structural dynamic models. Among other things, these models are used to predict flutter behavior and plan safety critical flight tests. Ground vibration testing is typically performed late in the development cycle, and due to the limited availability of the aircraft, there is pressure to get the test results as quickly as possible.
Aircraft structural design must be carefully verified to meet performance requirements but also guarantee safety. On one hand, stringent regulations for reduced emissions call for more lightweight structures such as composite materials and innovative aircraft architectures, which creates lots of uncertainty around structural dynamic performance. On the other hand, new urban air mobility concepts enabled by electric propulsion offer possibilities for disruptive vertical take-off and landing (VTOL) aircraft configurations. This calls for more engineering work to validate and tune the performance of such innovative designs.
The goal of Ground vibration testing is to test program-critical flutter simulation results and reduce the risk of flight flutter tests. More specifically, this large-scale modal test on the full aircraft serves to calibrate computer-based finite element (FE) models used for further flutter predictions. The results of the test are the modal parameters of the aircraft structure and include modal frequencies, damping values, mode shapes and scaling factors for a number of configurations. During the Ground Vibration Testing (GVT) campaign, structural coupling tests involving the flight control system are also performed to help calibrate the simulation models and control laws. These calibrated aero-servoelastic models are then used for flutter predictions to analyze the behavior of the aircraft throughout its flight envelope and reduce the risk of the flight flutter test.
Aeroservoelasticity (ASE) is a multidisciplinary technology dealing with the interaction of the aircraft’s flexible structure, the steady and unsteady aerodynamic forces resulting from the aircraft motion, and the flight control systems.
Aeroacoustics Wind Tunnel Testing
The airframe noises generated by the landing gear, flaps, slats, or other high-lift devices are significant contributors to aircraft acoustic emissions, especially during the approach and landing phases. To help minimize aircraft noise pollution in the vicinity of airports, engineers need to evaluate and optimize the acoustic performance of aircraft concepts and models as early as possible.
Wind tunnel tests are effective to validate prediction models before the aircraft can fly. However, they are costly and require extensive test preparation time. We use advanced acoustics solvers for aeroacoustics engineering by using advanced solutions for highly efficient aeroacoustic wind tunnel testing.
Noise, Vibration and Harshness – NVH in eVTOL – (Electric Vertical Take-Off & Landing) and Electro-Motors
FEA based Simulation Design for Electromagnetic multiphysics environments has a significant benefits for noise, vibration and harshness (NVH) analysis of electrical machines and transformers. NVH is an important analysis required by manufacturers of motors used in hybrid/electric vehicles, appliances, commercial transformers and other applications where quiet operation is an essential design parameter. Two-way transient magnetostriction coupling enables the magnetostrictive forces to be added to the magnetic forces and coupled to a mechanical design to predict acoustic noise.
Results from Electromagnetics solver obtained from the transient electromagnetic simulation to calculate the forces which are directly mapped to Mechanical solvers through special co-simulation algorithms for harmonic analysis. Optionally, an acoustic analysis can be performed to study noise. The forces from Electromagnetics solver are mapped as force vectors within the volume of the individual mesh elements, allowing a detailed and accurate form of mapping. This is because element-based mapping allows forces to be calculated for individual mesh elements, increasing the accuracy.
To optimize for NVH, our engineers use the forces from the EM analysis to perform advanced vibro-acoustic simulations. The forces are mapped to evaluate the structural dynamics response of the motor. Modal and harmonic stress coupling responses are important for simulating the NVH of an electric motor and for proper vibro-acoustic design of eVTOL – (Electric Vertical Take-Off & Landing). The harmonic analyses generate absolute magnitudes of vibrations and waterfall diagrams to get a complete picture of the motor’s acoustic profile.
VTOL Cabin Thermal Comfort CFD Simulation
The passenger’s thermal comfort is an essential design-criterion for the air-conditioning and customization of a VTOL and eVTOL cabin. In industry, engineers conduct costly and time-consuming test series with specifically built cabin mock-ups to obtain some information about the expected passenger’s sensation of comfort already in the design process.
We use the CFD Simulation to predict the passenger’s comfort by means of advanced software such as MSC Cradle, OpenFoam, Star-ccm+ and Ansys Fluent and to allow for an interactive layout of an optimized cabin. The CFD-computations of the air flow in the cabin’s interior and the flow through cabin air outlets is optimized with the help flow simulations to achieve design specifications.
Electromagnetic challenges in VTOL and UAM – Urban Air Mobility development
Many technical challenges need to be tackled and solved such as the widespread use of composite materials, hybrid and fully electric propulsion systems, the potential for radio frequency (RF) interference due to the interaction among external electromagnetic environment and the vehicle’s RF systems, the safety of the passengers, and the management of air traffic.
The same technologies find increasing application in the new concept VTOL as well in those that are renewed to take advantages from new avionics system and innovative materials.
VTOL Aerodynamics Simulation
VTOL aerodynamic simulation is used to improve the aerodynamic performance and reducing the drag of VTOL. Objective of the simulation is to make accurate predictions of aerodynamic forces, Lift and Drag Coefficient etc.
While aerodynamics is at the core of all aerospace engineering programs, the broader discipline of fluid mechanics, encompassing both aerodynamics and hydrodynamics, covers a vast array of topics. Enteknograte engineering team use coupled MBD and CFD to simulate any VTOL and Drone related problems in world class simulation methods.
FEA based Simulation design of Electro-Motor
The advantages of Enteknograte simulation service and consultant to electric machine analysis that still face new demands for higher performance deriving further performance gains requires finite element analysis (FEA) to identify previously overlooked or underestimated aspects of machine design. These demands have increased competition among machine designers to extract the most performance from a design.
Our accumulated knowledge and experience in motor design enables us to provide powerful multiphysics simulation simulation technologies to evaluate complex phenomena such as thermal demagnetization and vibration in addition to basic characteristics such as induced voltage, torque, and inductance. Obtain induced voltage, load torque, cogging torque, inductance, flux linkage, iron losses, coil losses, magnet loss, permeance, parameter sensitivity, equivalent circuit model extraction, heat generation, temperature distribution, eccentricity, stress, vibrations, radiated sound, magnetization, demagnetization, and skew effects for different of motors:
- Brushless Permanent Magnet machine (BLPM)
- Induction (or Asynchronous) machine (IM)
- Wound Synchronous machine (SM)
- Switched Reluctance machine (SRM)
- Synchronous Reluctance machine
- Permanent Magnet External Rotor
Multiphysics Simulation: Electromagnetic–Structural Dynamics–Fluid–Acoustics
By coupling the electromagnetic field solution with other solvers, we examine coupled physics phenomena and achieve the highest fidelity solution to eliminate reliability problems and design safe and effective products. Combination of advanced FEA and computational tools lead to special platform that let us to manages the data transfer between physics solutions and handles solver interactions, so we can set up and analyze complex coupled-physics behaviors such as:
- Electromagnetic–Structural
- Electromagnetic–Structural with stress and strain coupling effects on on magnetic properties
- Electromagnetic–Fluids interaction with coupling of CFD and Electromagnetic Solvers
- Electromagnetic–Structural–Fluids
- Electromagnetic–Structural Dynamics–Acoustics
FEA (Finite Element Analysis) of Vibration Fatigue
Structural vibration can be a source for many product related problems; it can cause fatigue and durability problems as well as adverse reactions to the user or bystanders in the form of undesirable vibrations that can be felt or heard. As well, undesired structural vibrations can prevent products from operating as required and potentially becoming a safety concern. The Vibration Fatigue simulation predict fatigue in the frequency domain and it is more realistic and efficient than time-domain analysis for many applications with random loading such as wind and wave loads.
- Simulates vibration shaker tests driven by random PSD, swept-sine, sine-dwell, or sine-on-random loading
- FE models are solved for frequency response or modal analysis
- Vibration loading is defined in Fatigue simulation tools and can include effect of temperature, static offset load cases and complete duty cycles of combined loading
- Vibration fatigue loads can be used for SN and EN
Electronics Cooling: FEA and CFD based multiphysics simulation
Our FEA and CFD based multiphysics simulation design provides electronics cooling simulation products for chip, package and board thermal analysis as well as thermo-mechanical stress analysis. Multiphysics simulation tools help us to enhance reliability of the entire electronic system by managing excessive heat that can otherwise lead to increasing leakage and electromigration failure.
Electric motor cooling becomes critical as we want to move to higher power, high-efficiency equipment. Excess heat is produced that can greatly reduce efficiency and in extreme cases, permanent magnets can even reach their limit and become demagnetized. For such calculation we analyze the power losses and then use this information for a detailed thermal analysis. These results are used to predict the temperature rise within the motor configuration based on given operating conditions and to determine appropriate electric motor cooling mechanisms using advanced FEA and CFD based Thermal simulation tools. Many different forms of electric motor cooling can be simulated, including:
- Natural or forced air cooling
- Water cooling
- Spray cooling
Defense Technical Information for Aircraft Crash Survival Design Guide
This five volume publication has been compiled to assist design engineers in understanding the design considerations associated with the development of crash resistant U.S. Army aircraft. A collection of available information and data pertinent to aircraft crash resistance is presented, along with suggested design conditions and criteria.
The five volumes of the Aircraft Crash Survival Design Guide cover the following topics Volume I – Design Criteria and Checklists Volume II – Aircraft Design Crash Impact Conditions and Human Tolerance Volume III – Aircraft Structural Crash Resistance Volume IV – Aircraft Seats, Restraints, Litters and CockpitCabin Delethalization and Volume V – Aircraft Postcrash Survival. This volume Volume III contains information on the design of aircraft structures and structural elements for improved crash survivability.
Current requirements for structural design of U.S. Army aircraft pertaining to crash resistance are discussed. Principles for crash-resistant design are presented in detail for the landing gear and fuselage subject to a range of crash conditions, including impacts that are primarily longitudinal, vertical or lateral in nature and those that involve more complicated dynamic conditions, such as rollover. Analytical methods for evaluating structural crash resistance are described:
- Aircraft Crash Survival Design Guide: Design Criteria and Checklists.
- Aircraft Crash Survival Design Guide: Aircraft Design Crash Impact Conditions and Human Tolerance.
- Aircraft Crash Survival Design Guide: AIRCRAFT STRUCTURAL CRASH RESISTANCE
- Aircraft Crash Survival Design Guide: Aircraft Seats, Restraints, Litters and Cockpit/Cabin Delethalization
- Aircraft Crash Survival Design Guide: Aircraft Postcrash Survival
European Union Aviation Safety Agency Regulations
- Third Publication of Means of Compliance with the Special Condition VTOL – MOC-3 SC-VTOL Issue 1
- Second Publication of Means of Compliance with the Special Condition VTOL – MOC-2 SC-VTOL Issue 3
- Comment Response Document Issue 2 – MOC-2 SC-VTOL Issue 1
- Second Publication of Means of Compliance with the Special Condition VTOL – MOC-2 SC-VTOL Issue 2
- Second Publication of Proposed Means of Compliance with the Special condition VTOL – MOC-2 SC-VTOL Issue 1
- Means of Compliance with the Special Condition VTOL – MOC SC-VTOL Issue 2
- Proposed Means of Compliance with the Special condition VTOL– MOC SC-VTOL Issue 1
- CRD Proposed Means of Compliance with the Special condition VTOL– MOC SC-VTOL Issue 1
- Special Condition for small-category VTOL aircraft
- Special Condition for small-category VTOL aircraft – with highlighted text
- Proposed Special Condition for small-category VTOL aircraft
- Comment Response Document – EASA SC-VTOL-01
- First building block to enable safe VTOL operation and new air mobility in Europe
- Third building block to enable safe VTOL operation and new air mobility in Europe
Real world Simulation: Combination of experience and advanced analysis tools
Calling upon our wide base of in-house capabilities covering strategic and technical consulting, engineering, manufacturing and analytical software development – we offer each of our clients the individual level of support they are looking for, providing transparency, time savings and cost efficiencies.
Enteknograte engineers participate in method development, advanced simulation work, software training and support. Over experiences in engineering consulting and design development, enables Enteknograte’s engineering team to display strong/enormous client focus and engineering experience. The Enteknograte team supports engineering communities to leverage CFD-FEA simulation softwares and methodologies. It leads to the creation of tailored solutions, aligned with the overall product development process of Enteknograte clients.
CAE Simulation: CFD, FEA, System Modeling, 1D-3D coupling
Integrated expertise covering every Equipment component analysis. From concept through to manufacture and product launch, and for new designs or Equipment modifications, we provide engineering simulation expertise across projects of all sizes. Simulation has become a key enabling factor in the development of highly competitive and advanced Equipment systems. CAE methods play a vital role in defining new Equipment concepts.
