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Viewing 1 to 30 of 5183
2017-03-28
Technical Paper
2017-01-0182
Gautam Peri, Saravanan Sambandan, Sathish Kumar S
The intended primary objective of a passenger vehicle air conditioning system is to ensure thermal comfort to the passengers seated inside at all prevailing conditions. Presently 1D analysis plays a major role in determining the conformation of the selected system to achieve the desired results. Virtual analysis thus saves a lot of time, cost and effort in predicting the system performance in the initial development phase of the vehicle HVAC systems. A variety of parameters play an important role in achieving the above thermal comfort. In order to optimize the simulation, predicting the duct losses and cabin interior temperatures plays a vital role. Physical and geometrical parameters of the cabin are accurately modelled by considering all the parameters such as glass and sheet metal surfaces, air gaps, solar angles, solar intensity, instrumentation panel, firewall etc.
2017-03-28
Technical Paper
2017-01-0260
Yuanying Wang, Heath Hofmann, Denise Rizzo, Scott Shurin
The increasing electrification of military vehicles is also increasing the need for accurate models of electric motors and generators for use in powertrain design. In particular, there is a strong need to accurately model the internal temperatures of these machines. Thus, an accurate yet computationally-efficient thermal model is required. In previous work, a technique capable of dramatically reducing the order of a 3-dimensional finite-element (FE) thermal conduction model was developed. The developed model has acceptable accuracy but is orders of magnitude faster than the FE model. This new model was validated by a locked-rotor test with close agreement, but the results are unsatisfactory when the rotor is spinning, since the resulting heat convection behavior is not precisely modeled. This paper will present a computationally-efficient model of heat convection due to air circulation produced by rotor motion.
2017-03-28
Technical Paper
2017-01-0267
Tomasz Haupt, Gregory Henley, Angela Card, Michael S. Mazzola, Matthew Doude, Scott Shurin, Christopher Goodin
Pending OPSEC review
2017-03-28
Technical Paper
2017-01-0250
Jizhou Zhang, Jianhua zhou PhD, Mian LI, Min Xu
To improve the system performance, precision manufacturing is required for production of the internal combustion engines (ICEs), a typical complex nonlinear system. Previous studies show that tolerances of critical dimensions have significant impacts on the engine performance. Among many critical factors, friction loss is one of the most important ones that affect the output performance of ICEs. It is necessary to recognize and control the tolerances which affect the friction loss. Of all the friction pairs for the engine, it is observed that the piston-cylinder friction pair and the bearing system take up nearly 70% of the total friction loss. In this work a novel multi-objective tolerance design optimization problem considering two friction systems mentioned above is proposed and solved. First two separated simulation models, the piston-cylinder and the bearing are built using AVL Excite Piston & Ring® and AVL Excite Power Unit®, respectively.
2017-03-28
Technical Paper
2017-01-1225
Martin Hosek, Jayaraman Krishnasamy
An advanced electric motor with hybrid-field topology has been developed for automotive traction applications. Departing from the conventional radial- and axial-field designs, the hybrid-field motor features three-dimensional magnetic flux paths in a geometry that maximizes the effective volume for magnetic flux flow. The three-dimensional flux paths are enabled by an isotropic soft magnetic material, which has been engineered to replace conventional laminated winding cores with solid isotropic components. The material is produced by a novel additive-manufacturing process based on spray forming. The paper introduces the spray-forming process for motor stator components and presents a conceptual design of the traction motor developed around them, including the motor topology, stator construction and rotor construction. The stator features a spray-formed core with three-dimensional magnetic flux paths, high-density windings and direct liquid cooling.
2017-03-28
Technical Paper
2017-01-1141
Bashar Alzuwayer, Robert Prucka, Imtiaz Haque, Paul Venhovens
The objective of the research reported in this paper was to develop and utilize a high fidelity and computationally efficient model for an advanced 9-speed automatic transmission that features an innovative combination of positive clutches (interlocking dog clutches) and conventional wet clutches. The interlocking dog clutches utilization in automatic transmissions is a challenging task due to the need for seamless engagement of the clutches (avoiding clash) and the behavior of slip-less power transmission (shifts). This publication starts with in depth review of the literature related to transmissions equipped with interlocking dog clutches. Appropriate simulation models for the torque converter, the lockup clutch, transmission gearing system, interlocking dog clutches, wet clutches, hydraulic control valves and circuits were developed and integrated with a 1-D vehicle road load model.
2017-03-28
Technical Paper
2017-01-0264
Venkatesh Babu, Ravi Thyagarajan, Jaisankar Ramalingam
In this paper, the capability of three methods of modelling detonation of high explosives (HE) buried in soil viz., (1) coupled discrete element & particle gas methods (DEM-PGM) (2) Structured - Arbitrary Lagrangian-Eulerian (S-ALE), and (3) Arbitrary Lagrangian-Eulerian (ALE),are investigated. The ALE method of modeling the effects of buried charges in soil is well known and widely used in blast simulations today Due to high computational costs, inconsistent robustness and long run times, alternate modeling methods such as Smoothed Particle Hydrodynamics (SPH) and DEM are gaining more traction. In all these methods, accuracy of the analysis relies not only on the fidelity of the soil and high explosive models but also on the robustness of fluid-structure interaction. These high-fidelity models are also useful in generating fast running models (FRM) useful for rapid generation of blast simulation results of acceptable accuracy.
2017-03-28
Technical Paper
2017-01-0261
Randolph Jones, Robert Marinier III, Frank Koss, Robert Bechtel, John A. Sauter
When evaluating new vehicle designs, modeling and simulation offer techniques to predict parameters such as maximum speed, fuel efficiency, turning radius, and the like. However, the measure of greatest interest is the likelihood of mission success. One approach to assessing the likelihood of mission success in simulation is to build behavior models, operating at the human decision-making level, that can execute realistic missions in simulation. This approach makes it possible to not only measure changes in mission success rates, but also to analyze the causes of mission failures. Layering behavior modeling and simulation on underlying models of equipment and components enables measurement of more conventional parameters such as time, fuel efficiency under realistic conditions, distance traveled, equipment used, and survivability.
2017-03-28
Technical Paper
2017-01-0899
Paul Dekraker, John Kargul, Andrew Moskalik, Kevin Newman, Mark Doorlag, Daniel Barba
The Environmental Protection Agency’s (EPA’s) Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created to estimate greenhouse gas (GHG) emissions from light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types with different powertrain technologies, showing realistic vehicle behavior, and auditing of internal energy flows in the model. In preparation for the midterm evaluation (MTE) of the 2017-2025 light-duty GHG emissions rule, ALPHA has been updated utilizing using newly acquired data from model year 2013-2015 engines and vehicles.
2017-03-28
Technical Paper
2017-01-0518
Sebastian Hann, Lukas Urban, Michael Grill, Michael Bargende
For many aspects of engine development, 0D/1D-simulation has evolved into an important tool to obtain reliable results at passable effort, especially for transient operations. Based on the neces-sary simplification of the three-dimensional reality to one-dimensional models, 1D-simulation heavily depends on the quality of the used sub-models. For internal combustion engines, adequate modelling of combustion chamber processes is of essential importance. Quasi-dimensional approaches to describe SI-engine-like burn rates of natural-gas engines base mostly on the modelling of laminar flame speeds. However, direct measurements of laminar flame speeds are usually taken in the air-fuel equivalence ratio range of 0.7 to 1.7 and pressures of only several bar. Generally used approaches then extrapolate to unsurveyed ranges, which causes contradictory data for laminar flame speed values.
2017-03-28
Technical Paper
2017-01-0903
Sarp Mamikoglu, Jelena Andric, Petter Dahlander
Many technological developments in automobile powertrains have been implemented in order to increase efficiency and comply with emission regulations. Although most of these technologies show promising results in official fuel economy tests, their benefits in real driving conditions and real driving emissions can vary significantly, since driving profiles of many drivers are different than the official driving cycles. Therefore, it is important to assess these technologies under different driving conditions and this paper aims to offer an overall perspective, with a numerical study in simulations. The simulations are carried out on a compact passenger car model with eight powertrain configurations including: a naturally aspirated spark ignition engine, a start-stop system, a downsized engine with a turbocharger, a Miller cycle engine, cylinder deactivation, turbocharged downsized Miller engine, a parallel hybrid electric vehicle powertrain and an electric vehicle powertrain.
2017-01-12
WIP Standard
ARP5765B
This SAE Aerospace Recommended Practice (ARP) defines a means of assessing the credibility of computer models of aircraft seating systems used to simulate dynamic impact conditions set forth in Federal Regulations §14 CFR Part 23.562, 25.562, 27.562, and 29.562. The ARP is applicable to lumped mass and detailed finite element seat models. This includes specifications and performance criteria for aviation specific virtual anthropomorphic test devices (v-ATDs). A methodology to evaluate the degree of correlation between a seat model and dynamic impact tests is recommended. This ARP also provides testing and modeling best practices specific to support the implementation of analytical models of aircraft seat systems. Supporting information within this document includes procedures for the quantitative comparison of test and simulation results, as well as test reports for data generated to support the development of v-ATDs and a sample v-ATD calibration report.
2017-01-10
Technical Paper
2017-26-0238
Abhijit Kumbhar, Jagannath M Paranjpe, Nagesh Karanth
Abstract New process development of forging component requires in-depth knowledge and experience related to the process. Also it requires number of physical trials to arrive at optimum process and initial billet dimensions. With the help of reliable computer simulation tool, it is possible to optimize the complete forging process and billet dimensions. Simulation provides much more insight about the process and possible forging defects. This saves considerable time and money. This paper describes about a complete forging process designed for a complex component. With the help of metal forming simulation software, complete forging process was simulated and optimized. Forging defects were removed during optimization of the process. Billet weight optimization was also carried out. Deciding the preforming shape of the billet was the main challenge. An innovative pre-forging shape was arrived which resulted in eliminating one process stage.
2016-12-01
Magazine
Additive Manufacturing How 3D Printing Will Transform the A&D Support Chain Advances in Lightweight Electronics Protection Conformal Coatings Increase Reliability of Aerospace and Military Assemblies Powering Outer Space An In-Depth Look at Aerospace Battery Technology Using High Bandwidth Oscilloscopes to Analyze Radar and Electronic Warfare Systems Bio-inspired Airborne Infrastructure Reconfiguration (BioAIR) EMI Analysis Software Helps Telescope Group Simulate RFI Mitigation Epitaxial Growth of Rhenium with Sputtering Processing and Characterization of Polycrystalline YAG (Yttrium Aluminum Garnet) Core-Clad Fibers Multi-Scale Analysis of Deformation and Failure in Polycrystalline Titanium Alloys Under High Strain Rates Abrasion Testing of Products Containing Nanomaterials Spectrum Fatigue of 7075-T651 Aluminum Alloy under Overloading and Underloading
2016-10-24
Event
The session covers advances in the development and application of models and tools involved in multi-dimensional engine modeling: advances in chemical kinetics, combustion and spray modeling, turbulence, heat transfer, mesh generation, and approaches targeting improved computational efficiency. Papers employing multi-dimensional modeling to gain a deeper understanding of processes related to turbulent transport, transient phenomena, and chemically reacting, two-phase flows are also encouraged.
2016-10-17
Technical Paper
2016-01-2235
Prithwish Kundu, Riccardo Scarcelli, Sibendu Som, Andrew Ickes, Yan Wang, John Kiedaisch, M Rajkumar
Abstract Heat loss through wall boundaries play a dominant role in the overall performance and efficiency of internal combustion engines. Typical engine simulations use constant temperature wall boundary conditions [1, 2, 3]. These boundary conditions cannot be estimated accurately from experiments due to the complexities involved with engine combustion. As a result, they introduce a large uncertainty in engine simulations and serve as a tuning parameter. Modeling the process of heat transfer through the solid walls in an unsteady engine computational fluid dynamics (CFD) simulation can lead to the development of higher fidelity engine models. These models can be used to study the impact of heat loss on engine efficiency and explore new design methodologies that can reduce heat losses. In this work, a single cylinder diesel engine is modeled along with the solid piston coupled to the fluid domain.
2016-10-04
Event
Topics Include: Product Design and Manufacturing Integration Integrated Production Systems Software Simulation Virtual Manufacturing Direct Digital Manufacturing Analysis and Modeling Tools RFID Structural Health Monitoring/Management Advanced Metrology
2016-10-04
Event
Topics Include: Product Design and Manufacturing Integration Integrated Production Systems Software Simulation Virtual Manufacturing Direct Digital Manufacturing Analysis and Modeling Tools RFID Structural Health Monitoring/Management Advanced Metrology
2016-09-27
Technical Paper
2016-01-8122
Jiaqi Xu, Hwan-Sik Yoon, Jae Y. Lee, Seonggon Kim
Abstract A neural network-based computer vision system is developed to estimate position of an excavator manipulator in real time. A camera is used to capture images of a manipulator, and the images are down-sampled and used to train a neural network. Then, the trained neural network can estimate the position of the excavator manipulator in real time. To study the feasibility of the proposed system, a webcam is used to capture images of an excavator simulation model and the captured images are used to train a neural network. The simulation results show that the developed neural network-based computer vision system can estimate the position of the excavator manipulator with an acceptable accuracy.
2016-09-27
Technical Paper
2016-01-8113
Xiaohua Zeng, Guanghan Li, Dafeng Song, Sheng Li, Xianghua Li
Abstract To improve traditional heavy commercial vehicles performance, this paper introduces a novel hydraulic hub-motor auxiliary system, which could achieve auxiliary driving and auxiliary braking function. Firstly, the system configuration and operation modes are described. In order to achieve coordinating control and distribution of the engine power between mechanical and hydraulic paths, the paper proposes an optimal algorithm based on enhance of vehicle slip efficiency and the results show that displacement of hydraulic variable pump relates with the transmission gear ratio. And then the hydraulic pump displacement controller is designed, in which the feedforward and feedback strategy is adopted. Considering the characteristics of hydraulic hub-motor auxiliary system, a layered auxiliary drive control strategy is proposed in the paper, which includes signal layers, core control layers and executive layers.
2016-09-27
Journal Article
2016-01-8013
Marius Feilhauer, Juergen Haering, Sean Wyatt
Abstract The way to autonomous driving is closely connected to the capability of verifying and validating Advanced Driver Assistance Systems (ADAS), as it is one of the main challenges to achieve secure, reliable and thereby socially accepted self-driving cars. Hardware-in-the-Loop (HiL) based testing methods offer the great advantage of validating components and systems in an early stage of the development cycle, and they are established in automotive industry. When validating ADAS using HiL test benches, engineers face different barriers and conceptual difficulties: How to pipe simulated signals into multiple sensors including radar, ultrasonic, video, or lidar? How to combine classical physical simulations, e.g. vehicle dynamics, with sophisticated three-dimensional, GPU-based environmental simulations? In this article, we present current approaches of how to master these challenges and provide guidance by showing the advantages and drawbacks of each approach.
2016-09-20
Technical Paper
2016-01-1991
Syed J. Khalid
Abstract Aircraft subsystems essential for flight safety and airworthiness, including flight controls, environmental control system (ECS), anti-icing, electricity generation, and starting, require engine bleed and power extraction. Predictions of the resulting impacts on maximum altitude net thrust(>8%), range, and fuel burn, and quantification of turbofan performance sensitivities with compressor bleed, and with both high pressure(HP) rotor power extraction and low pressure(LP) rotor power extraction were obtained from simulation. These sensitivities indicated the judicious extraction options which would result in the least impact. The “No Bleed” system in Boeing 787 was a major step forward toward More Electric Aircraft (MEA) and analysis in this paper substantiates the claimed benefits.
2016-09-20
Technical Paper
2016-01-2026
Dhwanil Shukla, Nandeesh Hiremath, Narayanan Komerath
Abstract An architecture is proposed for on-demand rapid commuting across congested-traffic areas. A lighter-than-air (LTA) vehicle provides the efficient loitering and part of the lift, while a set of cycloidal rotors provides the lift for payload as well as propulsion. This combination offers low noise and low downwash. A standardized automobile carriage is slung below the LTA, permitting driveway to driveway boarding and off-loading for a luxury automobile. The concept exploration is described, converging to the above system. The 6-DOF aerodynamic load map of the carriage is acquired using the Continuous-Rotation method in a wind tunnel. An initial design with rear ramp access is modified to have ramps at both ends. The initial design shows a divergence sped in access of 100 mph. An effort to improve the ride quality using yaw stabilizers, failed as the dynamic behavior becomes unstable. The requirements for control surfaces and instrumentation are discussed.
Viewing 1 to 30 of 5183

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