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2016-09-20
Technical Paper
2016-01-2000
Mark Bodie, Thierry Pamphile, Jon Zumberge, Thomas Baudendistel, Michael Boyd
Cost and performance requirements are driving military and commercial systems to highly integrated, optimized systems which require more sophisticated, highly complex controls. To realize benefits of those complex controls and make confident decisions, the validation of both plant and control models becomes critical. To quickly develop controls for these systems, it is beneficial to develop plant models and determine the uncertainty of those models to predict performance and stability of the control algorithms. Validation for an air cycle machine model based on acceptance sampling and tolerance interval is presented here. The validation process described in this presentation is based on MIL-STD 3022 with emphasis on requirements settings and the testing process.
2016-09-20
Technical Paper
2016-01-1995
Patrick McCarthy, Nicholas Niedbalski, Kevin McCarthy, Eric Walters, Joshua Cory, Soumya Patnaik
As the cost and complexity of modern aircraft systems increases, emphasis has been placed on model-based design as a means for reducing development cost and optimizing performance. To facilitate this, an appropriate modeling environment is required that allows developers to rapidly explore a wider design space than can cost effectively be considered through hardware construction and testing. This wide design space can then yield solutions that are far more energy efficient than previous generation designs. In addition, non-intuitive cross-coupled subsystem behavior can also be explored to ensure integrated system stability prior to hardware fabrication and testing. In recent years, optimization of control strategies between coupled subsystems has necessitated the understanding of the integrated system dynamics.
2016-09-20
Technical Paper
2016-01-1998
Michele Trancossi, Jose Pascoa, Carlos Xisto
Environmental and economic issues related to the aeronautic transport, with particular reference to the high speed one are opening new perspectives to pulsejets and derived pulse detonation engines. Their importance relates to a very high thrust to weight ratio and very low cost of manufacturing. This papers presents a multi-chamber cooled pulsejet architecture, which has been specifically designed for reducing the vibrations induced by a single chmber and tube pulsejet architecture. After preliminary design considerations it will take into account the thermal problem of this very simple and unespansive propulsion system. It analyses the heat transfer process through the wall of the combustion chamber of a pulsejet for aeronautic propulsion. The inside wall is exposed to burning gases with an average temperature of 1200 K, which oscillates with an amplitude 500 k and a frequency of 50 hz.
2016-09-20
Technical Paper
2016-01-1999
Debabrata Pal, Frank Feng
Cooling of high current bus bars in aircraft power panels is performed by natural convection and radiation. Thermal analysis is done using Joule heating method where the heat dissipation in bus bar is computed based on current, specified resistivity, temperature coefficient of bus bar material and geometry of bus bar. In 3 phase AC application, there is additional heat dissipation due to skin effects and proximity effects. In addition, when the 3 phase AC is used to drive a motor at high frequency (1000-1400 Hz), this results in additional higher frequency harmonics, resulting in higher losses. In this paper a thermal and electrical FEA analysis is done for a bus bar system. For electrical loss model, Infolytica MAGNET is used to characterize losses in three parallel bus bars carrying AC at various frequencies. This loss analysis provided additional losses due to skin, proximity and higher frequency harmonics. Then this loss is incorporated the ICEPAK CFD thermal model.
2016-09-20
Technical Paper
2016-01-2054
Deniz Unlu, Federico Cappuzzo, Olivier Broca, Pierpaolo Borrelli
This paper presents the activities foreseen on the Finmeccanica EIS (Entry In Service) 2020 derivative aircraft performed in the frame of the FP7 European research project TOICA (Thermal Overall Integrated Concept of Aircraft). On board air systems for conventional aircrafts are fed by the bleed off-take which penalizes the amount of power available to the power turbine of jet or turboprop engines. In order to minimize such operating penalties and optimize the energy efficiency of the overall aircraft, it is of major interest to support trade-off at aircraft level including aircraft systems as early as possible in the development cycle. The study presents the Virtual Integrated Aircraft methodology and associated simulation activities relying on the system simulation platform LMS Imagine.Lab. Several aircraft configurations and ECS packs architectures are studied and the different steps of the methodology are shown up to the trade between different aircraft configurations.
2016-09-20
Technical Paper
2016-01-1994
Wei Wu, Yeong-Ren Lin, Louis Chow, Edmund Gyasi, John P. Kizito, Quinn Leland
For aircraft electromechanical actuator (EMA) cooling application, the main objectives in axial fan design are high pressure head and high efficiency over a wide operating range including speed variation 1x~3x and pressure 0.2~1atm variation. The fan is based on a thickness of 2.54 cm, 48 mm hub, 86 mm fan diameter. The purpose of this study is to characterize a fan's performance at various rotational speeds and various ambient pressures, from 0.2 atm to 1 atm. Methodology An 86-mm diameter axial fan for electromechanical actuators was designed. The blade shape was obtained by optimization design of the radial blade using CFD technique. Geometrical parameters describing the variations of the blade profile were determined by hub contour and fan’s required parameters given above. The 3,5, 7-blade configurations were compared with the optimal blade profile. A commercial brushless DC axial fan motor is chosen. The fan blades were 3-D printed and tested in a closed test loop.
2016-09-20
Technical Paper
2016-01-1997
Wei Wu, Yeong-Ren Lin, Louis Chow, Edmund Gyasi, John P. Kizito, Quinn Leland
Recently there has been increasingly research interest on aircraft electromechanical actuator (EMA) safety. One approach to prevent EMAs from overheating is to use air cooling fans. Aircraft EMA cooling fan is a critical component because an EMA failure due to overheating could lead to a catastrophic failure in aircraft. Methodology A five-blade and seven-blade dual-fan designs are proposed. Each fan has its own independent shaft running in opposite rotating directions. Fan motors are assumed to be brushless direct current (BLDC) motors. After summarizing the possible failure causes and failure modes of BLDC fans by focusing on each failure mechanism, the life expectancy of fan ball bearings based on a major failure mechanism of lubricant deterioration was calculated and compared to such information in the literature. Finally, the advantages and disadvantages of three fault-tolerant approaches are discussed.
2016-09-20
Technical Paper
2016-01-2023
Timothy Deppen, Brian Raczkowski, Marco Amrhein, Jason Wells, Eric Walters, Mark Bodie, Soumya Patnaik
Future aircraft systems are projected to have order of magnitude greater power and thermal demands, along with tighter constraints on the performance of the power and thermal management subsystems. This trend has led to the need for a fully integrated design process where power and thermal systems, and their interactions, are considered simultaneously. To support this new design paradigm, the power quality analysis framework, developed previously, has been augmented to include thermal specifications. MIL-STD-2218 defines thermal design and cooling analysis requirements for airborne electrical equipment, while MIL-STD-704 defines transient, steady-state, and frequency-domain metrics for power quality. The proposed framework augments the power quality analysis framework developed for MIL-STD-704 and others, with a mathematical interpretation of the requirements given in MIL-STD-2218.
2016-09-18
Technical Paper
2016-01-1929
Nimrod Kapas, Ajith Jayasundera
There is an increasing interest in transient thermal simulations of automotive brake systems using CFD software. This paper presents a detailed high-fidelity simulation tool for modeling complete braking cycles including both the deceleration and the acceleration phases. During braking, this model applies the total heat input directly at the friction interface on the contacting rotor and pad surfaces. Based on the conductive heat fluxes within the surrounding parts, the solver automatically determines the division of the thermal energy flowing from the friction interface into the solid volumes of the rotor and the pad. The convective heat transfer between the surfaces of solid parts and the cooling airflow is simulated through conjugate heat transfer, and radiative heat exchange between solid surfaces is captured by using the discrete ordinates model.
2016-09-18
Technical Paper
2016-01-1935
Binyu Mei
With the continuous increasing requirements of commercial vehicle weight and speed on highway transportation, conventional friction brake is difficult to meet the braking performance. To ensure the driving safety of the vehicle in the hilly region, eddy current retarder has been widely used due to its fast response, lower prices and convenient installation. Electric eddy current retarder breaks the vehicle through the electromagnetic force generated by the current, and converted vehicle mechanical energy into heat through magnetic field. Air cooling structure is often used in the traditional eddy current retarder and cooling performance is limited, which causes low breaking torque, thermal recession, low reliability and so on. A water jacket has been equipped outside the eddy current region in this study, and the electric eddy current retarder is cooled through the water circulating in the circuit, which prolongs its working time.
2016-09-18
Technical Paper
2016-01-1941
Tie Wang, Xin Gao, Zhiwei Zhang
Vehicle hydraulic retarder is applied in heavy-duty trucks and buses as an auxiliary braking device. In traditional cooling system of hydraulic retarder, working fluid is introduced into heat exchanger to transfer heat to cooling liquid in circulation, whose heat is then dissipated by engine cooling system, not enabling waste heat of working fluid used effectively. In hydraulic retarder cooling system based on Rankine cycle, organic working fluid transfers heat with hydraulic retarder working fluid in Rankine cycle, and then outputs power through expansion machine. It can both reduce heat load of engine cooling system, and enhance thermal stability of hydraulic retarder while recovering and utilizing braking energy. First of all, according to the target vehicle model, hydraulic retarder cooling system model based on Rankine cycle is established.
2016-06-28
Standard
J1598_201606
This SAE Recommended Practice is applicable to all liquid-to-gas, liquid-to-liquid, gas-to-gas, and gas-to-liquid heat exchangers used in vehicle and industrial cooling systems. This document outlines the test to determine durability characteristics of the heat exchanger from vibration-induced loading.
2016-06-15
Technical Paper
2016-01-1814
Maxime Legros, Jean Michel Ville, Solène Moreau, Xavier Carniel, Christophe Lambourg, Guillaume Stempfel
Abstract The new requirements during the first stages of the conception of a HVAC prompt the designer to integrate the acoustic problematic increasingly upstream. The designer needs to select a coherent components’ choice in order to comply with the specifications in terms of aeraulic and acoustic performances. A tool has been created to guide the designer’s choices based on an acoustic synthesis which is a design and/or diagnosis approach used to analyze and predict the acoustic behavior of a complex system. The synthesis is developed in order to propose an approach which considers the integration effects and some interaction effects. The acoustic synthesis results are the starting point of a psycho-acoustic study providing audio samples of the prediction and indications of the HVAC acceptance by the prospective user. Also, one may compare the results of different acoustic synthesis projects to study the influence of the parameters on the acoustic prediction.
2016-06-15
Technical Paper
2016-01-1812
Saad Bennouna, Solène Moreau, Jean Michel Ville, Olivier Cheriaux
Abstract The noise radiated inside the car cabin depends on many sources such as the embedded equipments like the Heating, Ventilation and Air Conditioning (HVAC) module. An HVAC is a compact and complex system composed of several elements: blower, flaps, thermal exchangers, ducts… Air provided by an HVAC is blown by a blower passing through different components and then distributed to car cabin areas. Interactions between airflow and the HVAC fixed components generate noises that emerge in the car cabin. CEVAS project, managed by the automotive equipment manufacturer Valeo, is aiming to develop a prediction tool which will provide HVAC noise spectrum and sound quality data. The tool is based, in particular, on aeroacoustic characterization of individual elements and associations of elements.
2016-06-15
Technical Paper
2016-01-1810
Marie Escouflaire, Nicolas Zerbib, David Mas, Nicolas Papaxanthos, Saad Bennouna, Emmanuel Perrey-Debain, Boureima Ouedraogo, Solène Moreau, Jean Michel Ville
Abstract In the framework of noise reduction of HVAC (Heating, Ventilating and Air Conditioning) systems designed for cars, the present study deals with the numerical prediction of aeroacoustics phenomena encountered inside such devices for industrial purposes, i.e. with a reasonable CPU time. It is then proposed in this paper to assess the validity of the chaining, via Lighthill-Curle analogy, of a DES (Detached Eddy Simulation) resulting from the CFD code OpenFOAM (ESI Group) versus a RANS-LES (Large Eddy Simulation) and a BEM calculation resulting from the Vibro/Aeroacoustics software VA One (ESI Group) on an academic case of air passing through a rectangular diaphragm at a low Mach number. The BEM code being parallelized, the performances of DMP (Distributed Memory Processing) solution will also be assessed.
2016-06-15
Journal Article
2016-01-1808
Manfred Kaltenbacher, Andreas Hüppe, Aaron Reppenhagen, Matthias Tautz, Stefan Becker, Wolfram Kuehnel
Abstract We present a recently developed computational scheme for the numerical simulation of flow induced sound for rotating systems. Thereby, the flow is computed by scale resolving simulations using an arbitrary mesh interface scheme for connecting rotating and stationary domains. The acoustic field is modeled by a perturbation ansatz resulting in a convective wave equation based on the acoustic scalar potential and the substational time derivative of the incompressible flow pressure as a source term. We use the Finite-Element (FE) method for solving the convective wave equation and apply a Nitsche type mortaring at the interface between rotating and stationary domains. The whole scheme is applied to the numerical computation of a side channel blower.
2016-06-03
Magazine
Executive viewpoints Industry leaders offer their insights on the state of the heavy-duty on- and off-highway industries in this annual series of opinion pieces. The executives share their views on the most pressing technologies and trends shaping their business and the industry moving forward. Annual Product Guide Top products from throughout the industry covering technologies such as Powertrain & Energy, Hydraulics, Electronics, and Testing & Simulation.
2016-06-02
Magazine
A 24-hour battle of speed and efficiency At Le Mans this month, amped-up hybrid prototype racecars from Audi and Toyota face a revamped Porsche 919 hybrid, while Ford hopes to recapture glory with its new GT-R. Pushing the ICE forward, gradually Emergent technologies from BorgWarner, Eaton and Mahle aim for greater efficiency in gasoline and diesel engines. Smile, you're on Magna camera! Magna Electronics is rapidly expanding production of its made-in-U.S.A. onboard cameras to keep pace with booming OEM demand for safety and vehicle-autonomy vision-systems technology. Multi-material body solutions: Possibilities and manufacturing challenges The body-in-white is a prime target for lightweighting and many automakers are pursuing unique and effective multi-material approaches, but improved design tools and processes might yield greater gains.
2016-05-24
Standard
ARP594E
The requirements presented in this document cover the design factors which might cause any part of an electrically motor driven fuel pump assembly to act as an ignition source for explosive fuel vapors within the airplane tank.
2016-05-24
Standard
ARP5374B
This SAE Aerospace Recommended Practice (ARP) applies to Point-Of-Use, Central and Mobile Pre-Conditioned Air Equipment. It does not apply to aircraft mounted equipment.
2016-05-10
Standard
J3073_201605
This document surveys the systems used for thermal management of batteries in vehicles. Battery thermal management is important for battery performance and cycle life. The document also includes a summary of design considerations for battery thermal management and a glossary of terms.
2016-05-02
Magazine
UAV Technology Using SWaP-C Reductions to Improve UAS/UGV Mission Capabilities UGV Technology Designing Rugged Computing Platforms for UGVs UUV & Robotics Technology Bi-manual Dexterous Manipulation for Maritime Explosive Ordnance Disposal UUV Technology Applying UUV Advances to Safeguard Harbors and Littoral Waters Robotics Technology Designing a Robot to Counter Vehicle-Borne Improvised Explosive Devices
2016-05-01
Journal Article
2015-01-9148
Saeed Asgari, Shailendra Kaushik
Abstract A linear parameter varying (LPV) reduced order model (ROM) is used to approximate the volume-averaged temperature of battery cells in one of the modules of the battery pack with varying mass flow rate of cooling fluid using uniform heat source as inputs. The ROM runs orders of magnitude faster than the original CFD model. To reduce the time it takes to generate training data, used in building LPV ROM, a divide-and-conquer approach is introduced. This is done by dividing the battery module into a series of mid-cell and end-cell units. A mid-cell unit is composed of a cooling channel sandwiched in between two half -cells. A half-cell has half as much heat capacity as a full-cell. An end-cell unit is composed of a cooling channel sandwiched in between full-cell and a half-cell. A mass flow rate distribution look-up-table is generated from a set of steady-state simulations obtained by running the full CFD model at different inlet manifold mass flow rate samples.
2016-04-08
Magazine
Software's role continues to expand Design teams use different technologies to create new software and link systems together. Emissions regulations and engine complexity With the European Commission announcing a Stage V criteria emissions regulation for off-highway, scheduled to phase-in as earlly as 2019, there will be an end to a brief era of harmonized new-vehicle regulations. Will this affect an already complex engine development process? Evaluating thermal design of construction vehicles CFD simulation is used to evaluate two critical areas that address challenging thermal issues: electronic control units and hot air recirculation.
2016-04-07
Magazine
Defying the disruptors and driving innovation Four top engineering executives discuss how their "traditional" companies are finding new technology opportunities and business growth amid the start-ups-and are even doing some disrupting themselves. Preparing for a 48-volt revival The quest to improve fuel economy is not waning, nor is the desire to achieve higher mpg through the use of just the right lightweight material for the right vehicle application. Additive manufacturing enhances GTDI pistons Selective Laser Melting may help manufacture future gasoline-engine pistons with enhanced heat-transfer properties and reduced weight.
2016-04-05
Technical Paper
2016-01-0900
Sijia Zheng, Wen Fan
Abstract About 40% of the fuel energy in an internal combustion engine is lost as exhaust heat. Thermoelectric generators (TEGs) can recover the heat energy in the exhaust gas, improving the fuel efficiency of the vehicle and reducing emissions. In this study, a method of setting up TEG model using real testing data is proposed; model of a TEG-based vehicle power system is built; and the potential of the TEGs to improve the fuel efficiency of conventional vehicles and hybrid electric vehicles (HEVs) is examined by integrating the TEG into the vehicle power bus as a second generator. Firstly, output power model of one thermoelectric module is constructed in MATLAB/Simulink according to testing data, which is convenient and convincing. Then the model of TEG system is built using Matlab/Simulink software, taking the temperature distribution of the heat exchanger into consideration.
2016-04-05
Technical Paper
2016-01-1311
Tsuyoshi Kanuma, Katsumi Endo, Fumiaki Maruoka, Hiroshi Iijima, Makoto Kawamura, Keisuke Nakazawa, Eiki Yanagawa
Abstract 1 The vane-type rotary compressor of a heating, ventilating, and air conditioning system (HVAC system) is simple and compact but may emit noise due to the collision between the vanes and the cylinder wall. Several studies have been conducted on this chattering noise, with a focus on the noise associated with the compressor revolution speed, temperature, suction pressure, and exhaust pressure. However, such investigations are not sufficient to reveal the behavior of the vane movement in its entirety. To minimize the chattering noise, the details of the mechanism of such vane-operating noise must be investigated by analyzing the behavior of the vanes as a function of time. The vanes move according to the balance between the front and rear pressures. This report describes a novel visualization technique with which to monitor the motion of a vane under given operating conditions. In addition, a method of measuring the pressure affecting the movement of the vanes is discussed.
2016-04-05
Technical Paper
2016-01-1683
Blago B. Minovski, Lennart Lofdahl, Peter Gullberg
Abstract Presented are results from numerical investigations of buoyancy driven flow in a simplified representation of an engine bay. A main motivation for this study is the necessity for a valid correlation of results from numerical methods and procedures with physical measurements in order to evaluate the accuracy and feasibility of the available numerical tools for prediction of natural convection. This analysis is based on previously performed PIV and temperature measurements in a controlled physical setup, which reproduced thermal soak conditions in the engine compartment as they occur for a vehicle parked in a quiescent ambient after sustaining high thermal loads. Thermal soak is an important phenomenon in the engine bay primarily driven by natural convection and radiation after there had been a high power demand on the engine. With the cooling fan turned off and in quiescent environment, buoyancy driven convection and radiation are the dominating modes of heat transfer.
2016-04-05
Technical Paper
2016-01-0008
Johnathan Putrus, Stanley Jones, Badih Jawad, Giscard Kfoury, Selin Arslan, Peter Schihl
Thermal management systems (TMS) of armored ground vehicle designs are often incapable of sustained heat rejection during high tractive effort conditions and ambient conditions. During these conditions, which mainly consist of high torque low speed operations, gear oil temperatures can rise over the allowable 275°F limit in less than twenty minutes. This work outlines an approach to temporarily store excess heat generated by the differential during high tractive effort situations through the use of a passive Phase Change Material (PCM) retrofit thereby extending the operating time, reducing temperature transients, and limiting overheating. A numerical heat transfer model has been developed based on a conceptual vehicle differential TMS. The model predicts the differential fluid temperature response with and without a PCM retrofit. The developed model captures the physics of the phase change processes to predict the transient heat absorption and rejection processes.
2016-04-05
Technical Paper
2016-01-0255
Yinhua Zheng
This paper addresses R1234yf A/C system performance impacted by condenser airflow passage blockages of nonhotspot and hotspot objects. With the modern vehicle design trend, more and more chances exist in blocking condenser airflow passages by objects such as TOC (transmission oil cooler) or fine grills etc. These objects create hotspots and narrowed airflow passages to the condenser and result in A/C performance degradation. It is important to understand the specific area of the condenser which is most impacted by a blockage so this area can be avoided in the design/packaging of front end components. In addition, it is important to understand the magnitude of performance loss associated with the specific areas of blockage. As a result of this understanding, optimal design locations for these blockages (including hotspots and grilles) can be proposed in order to mitigate the impact on A/C cooling performance.
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