Finite Element Mesh Variation as Quality Assurance in Space Charging
EMA3D has tools which, when used in combination with Nascap-2K, provide the user a comprehensive and sophisticated space charging analysis framework. One of the key capabilities that EMA3D provides is the ability to control the finite element mesh which serves as the basis for a Nascap-2K simulation object.
Control over the mesh within the EMA3D set of tools includes control over both the meshing algorithm and the mesh resolution. Both of these aspects of the mesh are important to an analysis program. Different mesh algorithms may represent different areas of the vehicle more accurately. Some are stronger at maintaining the curvature of surfaces, while others are better at providing uniformity in the mesh gradient.
A finer mesh resolution generally provides more accurate results than a coarser mesh, however, a finer mesh takes longer to simulate. In Nascap-2K the simulation time scales as the number of elements squared. It is then desirable to find the coarsest mesh resolution which is still numerically accurate.
By using different simulation mesh algorithms and resolutions, the user can get a sense of the numerical accuracy and stability of their simulation results. We present a flow chart that represents one possible strategy for using multiple meshes as the foundation of an accurate and stable simulation program:
In this post, we flesh out some of the details of our flow chart and show how using multiple meshes can provide insight and confidence in the numerical accuracy of simulation results.
We show our simulation model in the figure below, where we have chosen three different mesh algorithms with roughly the same resolution to begin our sensitivity analysis with. In the EMA3D/CADfix framework, the user starts with a geometrical model, assigns materials, and then meshes the geometry which gets directly exported as a Nascap-2K object. The user can easily generate new meshes using a convenient mesh wizard. New objects can be exported quickly, with the appropriate materials already assigned.
Our model shown in the Figure is a simple model with just four materials: solar panels (cyan), elimstat paint (magenta), windows (blue) and FRSI thermal material (red). The three different meshes are generated by three different algorithms that provide different combinations of curvature sensitivity and uniformity.
We simulate the model out to 10,000 seconds in a geosynchronous ‘worst case’ plasma. We consider both a shaded (eclipse) environment and one in which there is illumination on the back side of the vehicle (away from windows and FRSI).
We start by looking at the results for the shaded scenario across these three algorithms. We will look at sensitivity to the mesh resolution further down. Our results are shown in the Figure below, where we plot the absolute maximum voltage to plasma on the vehicle minus the absolute minimum voltage to plasma on the vehicle, all scaled relative to the DELM mesh result. By plotting in this way, we have an easy comparison across meshes for a relatively intuitive physical quantity.
When looking the plot, a couple of observations are in order. First, the green curve corresponding to the DELC mesh (curvature sensitive mesh) shows a discrepancy relative to the other two meshes. Second the green curve also appears to have some numerical fluctuations early in the simulation. Taken together, our initial impression is that the DELC mesh is less accurate than the DELM and DELT meshes. Our initial impression is also that these two meshes, DELM and DELT, are likely accurate since they are stable and agree with each other. However, in order to confirm these initial impressions, we look at the 3D plot of the voltage to plasma at the end of the simulation, which we show in the following Figure.
The Figure shows a color representation of the induced voltages at the final moment of simulation. We have included both the DELM and DELC meshes in the plot. When looking at the 3D plot, we see that the DELC mesh has trouble capturing the spatial gradient on the solar arrays. The results are choppy, especially compared to the smooth variation seen in the DELM mesh. This confirms our initial impression that the DELC mesh results should be viewed with skepticism for this scenario.
We now consider a variation in the resolution of the mesh. We have limited our analysis here to variations in the DELM mesh resolution. The figure shows results in the same format as above for three different resolutions – labeled Fine, Medium and Coarse. The number of mesh elements for each mesh is shown in the parenthesis next to the plot legend.
When looking at variations in the mesh algorithm there is always some uncertainty as to which mesh should represent ‘baseline’. However, when looking at variations in the mesh resolution, we can usually safely assume that the finer mesh is more reliable. Looking at the results in the Figure we see that the Coarse mesh (776 elements) shows clear discrepancy with the Fine mesh (3622 elements), but that the Medium mesh (2050 elements) agrees relatively well with the Fine mesh. In this case, the user may make a judgment based on the need for simulation speed versus the importance of numerical precision whether the Fine or Medium mesh is more suitable for their needs. It is also possible that another mesh, perhaps with 2500 elements, would be a good compromise.
We now consider the results across the three algorithms for the scenario with illumination, which are shown in the Figure. It is interesting to note in these results how much the DELC mesh results fluctuate relative to the other two meshes early in the simulation, but then they all converge toward later times.
While it is reassuring to see consistency across the meshes in the ‘steady state’ of the results, the early fluctuations seen in the DELC mesh again indicate this mesh should be viewed with skepticism. Although we have only plotted results relative to the DELM results as a ratio, the user can also plot the minimum and maximum voltages for each mesh separately. Doing that would highlight clearly that the DELC mesh shows numerical instability at early times.
In this post, we have presented a strategy for using multiple meshes as the foundation of an accurate and stable space charging simulation program. Our strategy takes advantage of the mesh and material capabilities present within the EMA3D/Nascap-2K interface. Within this interface, the user can quickly generate simulation objects from different mesh algorithms and resolutions. We have seen that numerical results can fluctuate between these different meshes and that by careful analysis the user can start to pinpoint which meshes are reliable and how fine a mesh resolution is required. These capabilities help lay the groundwork for an accurate and reliable space charging analysis program.
Advanced Electromagnetic Modeling for Space Applications
Presentations a recent seminar and webinar can be found below.
Today electromagnetic (EM) modelling plays an essential role in the development of challenging projects in every engineering field. This is especially true for space applications, where performances and design specifications have recently experienced an incredible increase in complexity.
This seminar will discuss the benefits of high fidelity EM modelling in standard applications such as antenna siting on satellites. Further, we will deal with non-conventional EMC (electromagnetic compatibility) problems such as the modelling of antennas mounted on re-entry vehicles in the presence of plasma cloud and analysis of the interaction of antennas with plasma plume emitted by ion thrusters.
This seminar is based on the experiences gained by IDS in more than 30 years as a consulting company participating in satellite programs such as Sicral, Lisa pathfinder, SAC-D, Oceansat, Galileo, SmallGeo and Cosmo SkyMed.
Presenter: Dr. M. Bandinelli
Biography: M. Bandinelli received his degree in Electronic Engineering in 1986 from the University of Florence discussing thesis on numerical methods for antenna array design.
Since then he joined IDS S.p.A. where he was involved in the development of advanced numerical codes for electromagnetic modelling focused on antenna design and space application. Currently Mauro is the Director of the “ElectroMagnetic Engineering (EME) Division”.
His main area of interest includes:
- Development of CAE tools design for electromagnetic applications;
- Advances in numerical methods for electromagnetic modelling:
- Full-wave techniques (Method of Moments, FEM, FDTD, MTL);
- Hybrid techniques (MoM-GTD, MoM-FEM, MoM-MTL);
- Asymptotic methods (GTD, PO, PTD);
- Antenna siting design on naval, airborne, earthbound and spaceborne platforms (radiation patterns, link budgeting and EMI problems);
- Antenna – plasma interaction;
- Propagation analysis and antenna analysis applied to radar-TLC system analysis;
- EMC analysis and design for electronic systems (for earth station, naval, avionic and
Bandinelli published about 100 original papers at international meetings and on technical journals, on topics related to his relevant experience.
Background and Motivation
Space vehicles re-entering the Earth atmosphere become shrouded by a “dense” plasma (bow shock wave). The plasma frequency exceeds 1 GHz in most of “cloud” around the vehicle. Link obstruction occurs in most directions, causing the “blackout” of the link to ground stations.
The ESA Atmospheric Re-entry Demonstrator (ARD) program investigated experimentally the link to NASA TDRSS satellite. At the time, existing simulation teams found replicating the experimental results challenging. In this whitepaper, we describe the new modeling technique developed that correlates well with the experimental data. The technique considers diffraction around the plasma “cup” in order to accurately capture the effects.
ADF Re-entry Simulation Module
With respect to space capsule re-entry antenna link for space vehicles, the communication black-out due t o the presence of plasma is one of the main challenges to overcome. The purpose of the ADF Re-entry simulation module is to provide all the means (input data interfaces, working procedures and modeling methods) necessary to analyze in depth this problem and support communication system and antenna design.
The steps include:
- Define the flight trajectory ephemeris (latitude, longitude, altitude)
- Define the ground station or data relay satellite location
- Define the plasma cloud (available from existing spacecraft CFD models)
The outputs of the module include:
- Antenna gain pattern maps and polar/Cartesian plots
- Induced structural currents
- Channel transfer function for each station in the time or frequency domain, with the temporal evolution
Purchase the Software or Engage the EMA Services Team
The correlation achieved with the test results is dramatic. The tools are easy to use and fit into a streamlined workflow. Contact EMA today for this software module. Alternatively, our services team can perform this modeling or train internal staff on its use in a cost effective manner.
Advanced CAE Tools for Spacecraft Charging Analysis with NASCAP-2K
EMA3D includes advanced CAE tools for spacecraft charging analysis with NASCAP-2K. These tools allow the user to import native CAD (in almost any format) directly into the EMA3D platform to serve as the basis for their surface charging simulation, ensuring a detailed and accurate model. The user may also develop their model manually using powerful geometry development capabilities. The EMA3D platform enables the user to define and assign NASCAP-2K materials directly to sections of the model. There is no need to assign materials element-by-element within the NASCAP-2K environment, thereby reducing development time. The user can also easily control the mesh from within the EMA3D platform, including changing the mesh resolution and mesh algorithm. Finally, space charging results can be parsed with EMA3D or further simulated using EMA3D’s tools to propagate discharges to cables or antennas. We provide an example of the process from beginning to end.
For any questions feel free to contact us.
Full Webinar Presentation and Video
EMA3D includes advanced CAE tools to extend NASCAP-2K and provide spacecraft charging analysis for plasma interaction and EMC characterization in space. Many US companies rely on NASCAP-2K, but find the CAD and CAE tools, such as meshes, to be cumbersome and underdeveloped.
EMA3D gives the ability to simplify, modify, and defeature geometry to prepare for NASCAP-2K simulation. The EMA3D tools can then be used to assign the plasma interaction material properties. Then advanced meshing creates a valid conformal BEM mesh that imports cleanly into NASCAP-2K. Finally, the results can be parsed with EMA3D or further simulated using EMA3D’s tools to propagate discharges to cables or antennas.
The following gives an example of the process.
The example below shows a spacecraft from a internet-available CAD download. As you can see, the model is not yet defeautured and is not appropriate for NASCAP modeling yet.
Simplified, repaired and de-featured using EMA CADfix
The defeaturing is advanced, with automatic wizards and user-friendly tools.
BEM Mesh in EMA CADfix
Next, you can create a BEM mesh that is high quality and captures all the important elements of the geometry.
Opens Directly in NASCAP, with Materials Included
This allows the plasma engineer to take advantage of the good parts of NASCAP and omit the parts that are not advanced. The materials in this example are for illustration and are not realistic.
NASCAP Sample Results
One can view the results in NASCAP or export them to EMA3D. Further, more processing such as discharge coupling can be performed in EMA3D using the FDTD EM solver.
EMA3D FDTD Mesh
The EMA3D FDTD mesh of the same geometry is shown below. This is a general solver that can couple fields and waves as necessary to determine the threat to systems.
EMA recently published a paper at the AREMA Railway Exchange conference in Minneapolis, MN entitled: “SYSTEM LEVEL FULL SCALE LIGHTNING TESTING OF PTC WAYSIDE C&S SYSTEMS.” A summary of the paper follows:
Positive Train Control requires a high degree of reliability and availability. In order to meet these requirements, CSX needed to ensure the lightning protection of its wayside installations. In order to verify the CSX lightning protection design, an extensive full scale test and validation of all lightning protection devices and their applications was accomplished.
The following items are discussed:
- CSX Lightning Protection Approach
- Summary of CSX PTC Lightning Protection Features
- PTC Lightning Test Articles
- Application of Numerical Simulations of Lightning Strikes to Wayside Signal Systems
- Example Test Results
- Summary of Results
- Recommendations for Improvement
A PowerPoint presentation of this paper can be viewed at the bottom of this page.
CSX’s implementation of Positive Train Control must ensure the reliability of wayside equipment.
A critical part of reliability is effective lightning protection. In order to verify the lightning protection approach, CSX performed extensive full scale testing of wayside PTC installations. This PTC system-level lightning test is the first of its kind in the railroad industry.
This test of two fully CSX configured PTC bungalows to threat level lightning is an innovative concept that provided a unique opportunity for verification of the CSX lightning protection approach that has been applied since 1998.
The test demonstrated the effectiveness of the protection approach, and also provided suggestions for future improvement.
CSX LIGHTNING PROTECTION TECHNICAL APPROACH
The Foundation of CSX Lightning Protection
In 1998, CSX decided that the foundation of its lightning protection approach must be consistent with the following objective:
Eliminate Train Control service interruptions and signal equipment losses due to lightning related incidents.
This objective is consistent with that of other highly reliable systems in other industries for which there is no option for system failure. These include military command and control facilities, commercial aircraft, and other ground based critical systems.
Basis of Approach
The CSX protection approach is similar to that of other industries, and is based on the considerations of stress vs. strength.
In this case, stress is the incident lightning environment, which is quantified in terms of peak current, available energy, available charge, and current rate of rise.
Strength is a measure of the ability of the system to withstand the stress.
Stress and strength are compared to create the effectiveness of the protection approach. This effectiveness is stated in terms of the margin which equals the ration of strength/stress. For effective protection, the margin should be much larger than 1. If the stress is greater than strength, more protection is required.
Stress, the strength of the lightning environment, can be determined from several sources. First, field experience can be used to estimate the lightning levels that would be responsible to cause the observed damage. Second, Computational Electromagnetics can be used to perform numerical simulations of lightning strikes to wayside systems in order to characterize lightning currents that are incident on the wayside electronics and protection devices. Finally, the AREMA Signal Manual provides guidance in the lightning environment suitable for protection design.
SUMMARY OF CSX PTC LIGHTNING PROTECTION FEATURES
Basic Lightning Protection Rule
The basic rule of lightning protection is: Don’t allow lightning inside the bungalow! The critical PTC electronics are inside the bungalow, so if lightning cannot penetrate the bungalow, then the electronics are safe.
In order to accomplish this, the following protection features are implemented:
- Metal bungalow
- Faraday cage
- GE Tranquell AC arrester
- RF coaxial in-line bulkhead arresters
- Hybrid Low Voltage Arrester (HLVA) arrester for circuits having operating voltages less than about 30 volts
- Grounding of spares and shields at both ends of cables
These are discussed in the following paragraphs.
The metal skin provides an excellent shield upon which to apply protection for the lightning points of entry (POEs).
The cage is basically an extension of the bungalow surface inside the house, such that the house interior is a clean environment, and the interior of the Faraday cage contains the arresters and is the dirty external environment. Clean wires exit the cage with a very short lead length from the arrester, minimizing dirty environment coupling to the clean wires.
GE Tranquell AC arrester
This is mounted in its own small metal box (another Faraday cage) and has nearly zero lead length for its arrester return paths. The surface area and small lead length of this arrester ensures a low impedance path that will minimize let-through voltages.
RF Coaxial In-Line Bulkhead Arrester
Below is an interior view of a bulkhead mounted RF coaxial cable arrester.
Hybrid Low Voltage Arrester (HLVA)
This is the HLVA that is used to protect low voltage circuits. It has the smallest let-through voltage of any arrester CSX has tested since 1998. It has never failed in a shorted mode in either extensive testing or in the field.
Grounding of Spares and Shields
The image illustrates the grounding of shields and spares at both ends. The grounding is done within the dirty volume of the Faraday cage.
PTC TEST OVERVIEW
There were 155 test shots with as much as 120 kA injected lightning current as follows:
- Track circuits (Electrologixs) and arresters: 73 shots
- Signal lamps (Electroblox and relay) : 31 shots
- Communication and I/O cables between houses: 25 shots
- AC power: 7 shots
- RF links: 19 shots
- Satcom: 10 shots
- iNet: 5 shots
- Cellular: 4 shots
PTC LIGHTNING TEST CONFIGURATION
The test articles consisted of two fully configured PTC bungalows as shown below. The internal equipment consisted of the following:
- CNA 2000 Communications Network Adaptor
- ElectroLogIXS VLC and EC5
- ElectroBlox Standalone Wayside Interface Unit
- MDS iNET 900 transceiver
- A shielded six pair cable connection was also included from the A house to the B house, of which one pair was used.
- A shielded 12 wire signal I/O cable also connects the A and B houses
- Satellite connection with the iDirect Evolution 5 box via a satellite dish
- Cellular connection via the Digi Transport WR44 box
- RuggedCom RS930L switch
- Battery chargers and batteries
- Internal Faraday Cage containing arresters
- House ventilation and lighting systems
CSX provides redundant IP communication paths into the PTC equipment enclosures as follows:
- Local IP connection via telecom cable if available
- Cellular connection
- Satellite connection
- A few remote locations may use a 220 MHZ radio to communicate to the locomotive directly instead of the IP connection back to the control center and to the 220 MHz base stations.
NUMERICAL SIMULATIONS OF LIGHTNING STRIKES TO WAYSIDE SYSTEMS
The PTC lightning test was supported with computational electromagnetic simulations of strikes to wayside installations. This provides a first principles estimate of the lightning current waveforms (i.e., the stress) incident on wayside systems to supplement AREMA waveforms.
Stress is a combination of the following attributes:
- Peak current with units of amperes
- Available energy: Action Integral = ∫i(t)2dt with units of Joules/ohm (also = A2-seconds)
- Total charge: ∫i(t)dt with units of Coulombs
Lightning strikes to a typical CP location were numerically simulated with the software EMA3D from Electro Magnetic Applications (www.ema3d.com), which has been used on aerospace and military projects worldwide.
The incident lightning current is the standard 1% waveform commonly used for protection design of aircraft and ground stations.
The computational model is shown below. Four 200 kA lightning strikes were analyzed as follows:
- Strike to Bungalow
- Strike to Track
- Strike to Ground
- Strike to Signal Mast
The computed results included currents on track wires and signal wires. An example is shown below. The largest lightning currents induced on track wires and signal lamp wires are as follows:
- Track wires
- Largest, for a strike to a rail
- Amplitude: 95 kA
- Action integral: 430 kJ/Ω
- Second largest, for a strike to the bungalow or signal mast
- Amplitude: 26 kA
- Action integral: 55 kJ/Ω
- Signal cable, for a strike to a signal mast
- Amplitude: 170kA
- Action integral: 1600 kJ/Ω
- Largest, for a strike to a rail
PTC TEST RESULTS SUMMARY
The results of the PTC test are summarized as follows:
- No electronic units in the houses were damaged.
- Momentary upsets were observed, all self recovered
- Electrologixs: 30 sec recovery
- iNet radio: momentary dropout, 30 sec recovery (closing the Faraday cage doors remedied this)
- VDSL: momentary dropout: 30 sec recovery
- AC Protection: GE Tranquell performed best of the arresters tested
- HLVA was the best performing low voltage arrester
- RF interfaces: all passed, but inconsistent behavior of Satcom arrester
- Bonding of cable shields and spare wires to bungalow skin on both ends is a highly effective protection method
- Faraday cage: highly effective
- Clean/dirty isolation
- Arrester ground lead short for minimum let-through
SUGGESTED DESIGN CHANGES
Several design changes were recommended as a result of this test: These included:
- The Tranquell installation could be improved by using MOVs on only L1 and L2, and by connecting the neutral directly to bungalow skin ground.
- Bulkhead arresters be added to the Satcom antenna design to eliminate lightning current penetration into the house.
- The low voltage arresters on the signal lamp circuits could be eliminated
Full Conference Presentation
Validation of Computational Electromagnetics Simulations to Support Aircraft Certification Projects for Direct and Indirect Effects of Lightning
Computation Electromagnetic (CEM) simulations play an ever increasing role in the analysis and support for aircraft certification projects. CEM can be used to evaluate electromagnetic environmental effects as well as EMC/EMI system problems for design and certification support. This analysis can be used early in projects to investigate aircraft designs and assess the need for protections schemes but also to provide valuable results to aid in certification support. Both stages of simulation can provide significant program cost benefits by reducing program testing and developing a complete understanding of the EM response of a particular aircraft design. In this webinar, a senior EM scientist with more than a decade of CEM experience will highlight recent published efforts demonstrating the success of a large scale CEM simulation validation effort for direct and indirect effects of lightning on a commercial aircraft program with a composite fuel tank. The webinar will cover the validation comparisons of experiment and simulation results for a sample wingbox and a full aircraft. It will also cover some critical aspects of modeling and simulation required to achieve good correlations with experimental results.
For any questions about the webinar, please contact us.
Full Webinar Video and Presentation
Come see our talks at ICOLSE 2015 in Toulouse, France! All three talks will be presented on September 9th. See below for details.
Lightning Direct Effects on Anisotropic Materials from Electro-Thermal Simulation will be presented by Bryon Neufeld on Sept. 9 at 15:20 in the Cassiopée presentation room. Here’s the abstract:
Mitigating lightning Direct Effects (DE) damage on aerospace vehicles is an important engineering challenge and is directly related to safety of flight. Depending on the threat level and materials involved, vehicle surfaces and other design features may need to be protected to help mitigate damage. Numerical simulation can provide insight into the amount of damage likely to occur during a lightning strike and can reduce the costs associated with an expensive testing program. We here present a new simulation tool for such analyses that we believe provides unique capabilities especially well-suited for the protection of aerospace platforms, and we apply this new tool to the analysis of lightning DE on an anisotropic composite surface. Our simulation tool is the combined framework of EMA3D and the Elmer thermal physics solver. This new analysis platform allows for the correct description of anisotropic materials at both the electrical and thermal level. By implementing DE analysis capabilities in EMA3D we find a comprehensive avenue through which to analyze a wide range of E3 concerns for an entire aerospace vehicle.
For the full report: Click Here.
Lightning Response of a Composite Wing Test Box: A Validation of Simulation Results will be presented by Cody Weber on Sept. 9 at 15:20 in the Spot presentation room. Here’s the abstract:
Currents with lightning waveforms were injected onto an aircraft wing test box comprising of carbon fiber reinforced polymer (CFRP) skins and spars. Computational electromagnetic (CEM) simulation results obtained with EMA3D, a finite difference time domain (FDTD) full wave solver, were compared with experimental data to validate analytical methods used as part of a certification program. An extensive measurement program was completed prior to the wing test box experiments in order to develop simulation techniques and establish material parameters applicable to complex CFRP skins covered with multiple expanded copper foils when interacting with lightning currents. Excellent correlation in wave shape and transient peak values is demonstrated for the majority of current and voltage comparisons providing confidence in a numerical approach to accurately characterize a complex aircraft system’s response to lightning.
For the full report: Click Here.
Computational Electromagnetic Modeling and Experimental Validation of Fuel Tank Lightning Currents for a Transport Category Aircraft will be presented by Cody Weber on Sept. 9 at 15:50 in the Spot presentation room. Here’s the abstract:
A full scale aircraft lightning test campaign was conducted to support compliance with AWM 525.981 and CFR 25.981 through validation of computational electromagnetic (CEM) models. The aircraft is injected with different lighting current attachment scenarios while measurements of currents, voltages and magnetic fields focused in the composite wing area. The high fidelity aircraft model has been resolved with EMA3D software. It includes accurate structural features, fasteners, wiring and systems tubing. The overall comparison between the full scale test results and the simulation results is very good both for the shape and the amplitude of the waveforms.
For the full report: Click Here.
Denver, CO and Pisa, Italy
Electro Magnetic Applications, Inc. (EMA) and Ingegneria Dei Sistemi (IDS) have entered into a strategic partnership to merge their comprehensive offering of electromagnetic CAE tools, consulting services and measurement services and bring them to the United States market.
EMA and IDS are pleased to announce that the IDS CAE products ADF/E-MIND and VIRAF are now available in the US. These tools and another IDS product, SHIP-EDF, already used by the US Navy, will be fully supported by EMA’s team of consultants and scientists.
Each tool is a multi-method product coupled to an intuitive frameworks that allows for more throughput and organization of modeling workflows. Each tool covers a specialized application area:
Each tool is designed as a multi-method product, and this, coupled with an intuitive framework, allows for more throughput and organization of modeling workflow. Each tool covers a specialized area.
- VIRAF is dedicated to modelling Radar Cross Section control/reduction in modern aircraft, including those with stealth features.
- Ship-EDF is dedicated to naval applications and integrates EMC, RCS and IR modelling for full ship design and life-cycle control.
- ADF/E-MIND is dedicated to antenna/array design and control of EMC/EMI risks aboard air and spacecraft. In addition, ADF/E-MIND includes specialized simulation procedures for space applications. These include modeling:
- Electric thrusters plasma plume effect at RF level
- Antennas mounted on re-entry vehicles (plasma sheet effect on RF) launchers.
- Communication links among vehicle and ground/space relay stations.
- Radiated emissions and radiated susceptibility (RE/RS) analysis with Oversized Cavity Theory
IDS implements integrated state-of-the-art numerical techniques to support “high-fidelity modelling”, covering the frequency range from DC to hundreds of GHz. These specialized methods include, among others:
- Surface-Partial Element Equivalent Circuit (S-PEEC)
- Multilevel Fast Multipole Algorithm (MLFMA )
- Iterative Physical Optics (IPO)
- Uniform Theory of Diffraction (UTD)
Each method is highly parallelized and accelerated via the latest algorithms including:
- Domain Decomposition
All computational solvers used with IDS tools have been validated against years of measured data from both mock-ups and operational platforms.
By merging IDS capabilities with EMA experience, customers can access a complete solution for antenna performance evaluation, antenna co-site analysis, EMI/EMC, HIRF, EMP, RCS assessment and lightning simulation. System integrators and antenna designers can use these validated tools during the full development lifecycle. These tools support initial design, integration, and optimization. The heritage and industry familiarity with these tools allows them to support validation or certification of any final system.
“IDS is excited about the opportunity to offer US customers a comprehensive solution that leverages the decades of experience of both IDS and EMA. The result for the customer will be confidence that they are supported by teams that are domain experts in all aspects of electromagnetic simulation of complex platforms. Together, IDS and EMA will provide software and consulting solutions to the US customer base in a streamlined manner” – Mauro Bandinelli
IDS CAE tools are available immediately through all EMA sales channels. Existing EMA3D customers will be offered special upgrade programs.
EMA is a world leader in the analysis of electromagnetic effects. EMA’s expert staff and state-of-the-art software suite have helped countless businesses and government entities solve their electromagnetic design and certification challenges since 1977. EMA has helped major air and spacecraft programs solve problems concerning system coupling to the electromagnetic environment including: lightning, HIRF, EMI/EMC, and EMP.
Notable EMA customers include: Lockheed Martin Space Systems, Bombardier Aerospace, Orbital-ATK, Airbus and Textron.
IDS is an independent systems engineering company which has been providing high technology services and integrated system solutions since 1980. In electromagnetic engineering, IDS provides computational tools for design, analysis, and lifecycle control of sensors and platforms. IDS also has advanced measurement capabilities and consultancy services. Internal IDS research and development efforts continuously update IDS capabilities in cutting edge application areas. Recent advances include metamaterials devices and ultra-wideband (UWB) sensors.
Notable IDS customers include: European Space Agency, Italian Space Agency, Thales Alenia Space France, Thales Alenia Space Italy, TNO, SSTL, OHB, Carlo Gavazzi Space, Selex Galileo, RUAG, and SAC – ISRO.
For more information visit the IDS page here
We have posted a new training which shows a DO-160 type measurement of a 22 AWG twisted shielded pair, and compares the test results with simulation results.
DO-160 is a document that outlines a set of minimal standard environmental test conditions and corresponding test procedures for airborne equipment. Section 22 focuses on the lightning induced transient susceptibility, and describes test methods in order to verify the capability of equipment to withstand various test transients which represent the induced effects of lightning. DO-160 is the standard to follow for certification testing.
The measurement described below is for training purposes only. In actual DO-160 testing, waveforms defined in the DO-160 document should be used.
In this measurement, a double exponential current waveform resembling lightning component A, but with 400 mA amplitude, is injected onto the shield of the cable. The cable shield was grounded to an aluminum sheet placed 2 inches below the cable, such that the current path was from the cable shield to the aluminum sheet, back to the generator ground. The open circuit voltage (VOC) was then measured at the end of the cable opposite the injection point. For this configuration, the only way for any current and voltage to couple to the twisted pair inside the shield is through the shield transfer impedance. The schematic of the measurement is shown below. A full demo video of the test, test setup, and the simulation can be viewed here. The demo can be downloaded from the training page.
The corresponding model is a simple model of a cable above a metal sheet created in EMA3D integrated with MHARNESS. The training goes through all of the steps for creating the model. Once the model is created and the simulation completed, the comparisons of the measured and modeled VOC should look like this: