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Viewing 1 to 30 of 6183
2015-09-29
Technical Paper
2015-01-2888
Devadatta Mukutmoni, Tristan Donley, Jaehoon Han, Karthik Mahadevan Muthuraman, P. David Campbell, Tom Mertz
Design and evaluation of construction equipments and vehicles constitute a very important but expensive and time consuming part of the engineering process. This is especially so because of the large number of variants and the relatively small production volume of each variant leading to large costs of engineering and design of vehicles as a proportion of total sales. A simulation based methodology could potentially reduce the cost and time of the entire design process. In this study, we look into an alternative simulation based approach to the design process. However, given the enormity of the task, we limit the scope of this investigation to design evaluation and improvement for thermal considerations only. In particular, thermal evaluation of the electronic control units are looked into.
2015-09-29
Technical Paper
2015-01-2809
Sajit Pillai, Julian LoRusso, Matthew Van Benschoten
Cylinder deactivation was evaluated both analytically and experimentally on a diesel engine. This paper evaluates cylinder deactivation for potential benefits in fuel consumption and exhaust thermal management for improved after treatment system performance. An analytical study was conducted using GT-Power to evaluate potential benefits of deactivation. The model was validated at low-load, steady-state points by optimizing Exhaust Gas Recirculation (EGR) and Variable Geometry Turbocharger (VGT) to maintain similar or acceptable emission levels between base and deactivated modes of operation. The results demonstrated significant improvements in Brake Specific Fuel Consumption (BSFC) for low and part load operating points along with higher exhaust gas temperatures. The analytical results offered enough potential benefit to warrant an experimental investigation. To validate the analytical results, an experimental evaluation was performed.
2015-09-15
Technical Paper
2015-01-2420
Henry A. Catherino
The heat generation rate of a lithium ion cell was estimated using a reversible heat generation rate equation. Because the equation is based on the energy conservation law, the influence of kinetically slow processes should be considered. In this analysis, the influence of kinetically slow processes is present but it is small within the domain of the test measurements. This approximation can be of significant usefulness for modeling the thermal response of single cells and multi-cell batteries.
2015-09-15
Technical Paper
2015-01-2418
Ricardo Gandolfi, Luiz Ribeiro, Jorge Oliveira, Kleber Paiva, Marcia Mantelli
Due to the increasing power density of onboard electrical and electronic equipments and heat dissipation in civil and military aircraft, more efficient ways of transferring heat and new cooling techniques are a necessity. A passive heat transfer prototype was developed and experimentally evaluated in laboratory, at flight and ground tests in an Embraer ERJ-170 test aircraft. The passive heat transfer device consists of a loop-thermosyphon with two condensers and a common evaporator, using water as the heat transfer working fluid. An electrical resistance and a variable power source were used to dissipate heat inside the evaporator, simulating heat transfer from an onboard electronics bay. The fuselage/external air stream and the air flow inside an air conditioning system duct were used as heat sinks. Prior to flight tests, laboratory tests were conducted simulating ground and flight operations.
2015-09-15
Technical Paper
2015-01-2416
Charles E. Oberly, Michelle Bash, Benjamin R. Razidlo, Travis E. Michalak, Fernando Rodriguez
An IPTMS hardware facility has been established in the laboratories of the Aerospace Systems Directorate of the Air Force Research Laboratory at Wright-Paterson Air Force Base. This hardware capability was established to assess the integration issues and analyze the transient behavior of a high power Electrical Power System (EPS) couple virtually to a Thermal Management System (TMS). The system incorporates the use of dynamic electrical load, engine emulation, energy storage, and emulated thermal loads operated to investigate dynamics under step load conditions. Hardware architecture and control options for the IPTMS are discussed.
2015-09-15
Technical Paper
2015-01-2415
Kyle Shimmin, Greg Russell, Robert A. Reuter, Steven Iden
A reduced order dynamic aircraft model has been created for the purpose of enabling constructive simulation studies involving integrated electrical power and thermal management subsystems using Multidisciplinary Design Optimization methods. Previous higher-order models that have been used for this purpose have the drawbacks of much higher development time, along with much higher execution times in the simulation studies. The new formulation allows for climbs, accelerations and turns without incurring computationally expensive stability considerations; a dynamic inversion control law provides tracking of user-specified mission data. To assess the trade-off of improved run-time performance against model capability, the reduced order formulation is compared to a traditional six degree-of-freedom model of the same air vehicle. Thrust command comparisons against the higher fidelity model are shown to be excellent.
2015-09-15
Technical Paper
2015-01-2582
Andre Silva, Nayeff Najjar, Shalabh Gupta, Paul D'Orlando, Rhonda Walthall
The main function of the Environmental Control System (ECS) is to deliver thermal control and cabin pressurization of the air for the comfort and safety of crew members and the passengers on-board. The Heat Exchanger of the ECS is the critical component that ensures healthy system operation and maintains this key function. The heat exchanger mainly exhibits the failure known as fouling, which is the accumulation of clogging due to contamination. For safe and efficient operation of the ECS under the complex environments of aerospace systems, it is necessary to develop the capability to diagnose degradation of system components in the early phase of fault evolution. Periodic maintenance of these components without knowledge of their remaining useful life estimates causes significant financial expenses for the airliners and unnecessary interruption of aircraft operation.
2015-09-15
Technical Paper
2015-01-2561
Fernando Stancato, Sandro Conceicao, Ramon Papa, Luis Santos
Nowadays CFD analysis including virtual manikins is vastly applied to evaluate thermal comfort inside different working environments, such as buildings cars and aircrafts. Inside aircraft cabins, added to the numerical challenges due to geometrical complexity, the available subjective responses used to judge occupant local thermal comfort are usually based on buildings and cars experiments. In the present paper however, it is applied an aircraft based subjective responses to evaluate thermal comfort which was specifically developed using regional jet mock-up experiments. The evaluation for the two approaches will be compared providing insight of the main differences.
2015-09-15
Technical Paper
2015-01-2419
Naoki Seki, Noriko Morioka, Hidefumi Saito, Hitoshi Oyori
This paper describes the concept of air/fuel integrated thermal management system, which employs VCS (Vapor Cycle System) for the refrigeration unit of ECS (Environment Control System) and exchange the heat between VCS refrigerant and the fuel into the engine, and present feasibility study to apply the concept to the future all electric aircraft system. The key component of the aircraft thermal management system is ECS. The heat generated in the aircraft is transferred to ECS heat exchanger by the recirculation of the cabin air and exhausted into the ram air. While some of the aircrafts employ the fluid heat transfer loop, the transferred heat is exhausted into the ram air as ever. The usage of ram air for the cooling will increase the ram drag and the fuel consumption, thus, less usage of ram air is preferable. Another source for heat exhaust is the fuel.
2015-07-13
Standard
ARP1796B
This SAE Aerospace Recommended Practice (ARP) discusses design philosophy, system and equipment requirements, installation environment and design considerations for military and commercial aircraft systems within the Air Transport Association (ATA) ATA 100 specification, Chapter 36, Pneumatic. This ATA system/chapter covers equipment used to deliver compressed air from a power source to connecting points for other systems such as air conditioning, pressurization, ice protection, cross-engine starting, air turbine motors, air driven hydraulic pumps, on board oxygen generating systems (OBOGS), on board inert gas generating systems (OBIGGS), and other pneumatic demands.
2015-07-08
Standard
J3030_201507
The purpose of this SAE Standard is to establish the specific minimum equipment requirements for recovery/recycling/recharge equipment intended for use with both R-1234yf and R-134a in a common refrigerant circuit that has been directly removed from, and is intended for reuse in, mobile air-conditioning (A/C) systems. This document does not apply to equipment used for R-1234yf and R-134a having a common enclosure with separate circuits for each refrigerant, although some amount of separate circuitry for each refrigerant could be used.
2015-07-01
Standard
J1726_201507
This SAE Recommended Practice provides test methods and criteria for evaluating the internal cleanliness and air leakage for engine charge air coolers. This SAE Recommended Practice also provides nomenclature and terminology in common use for engine charge air coolers, related charge air cooling system components, and charge air cooling system operational performance parameters.
2015-06-30
Standard
J3062_201506
The Scope of SAE J3062 covers hose intended for containing and circulating lubricant, liquid and gaseous R134a and/or R-1234yf refrigerant in automotive air-conditioning systems. The hose shall be designed to minimize permeation of the refrigerant, contamination of the system, and to be functional over a temperature range of -30 to 125 °C. Specific construction details are to be agreed upon between the user and supplier. Requirements for the hose used in coupled automotive refrigerant air-conditioning assemblies had been included in SAE J2064. SAE J3062 separates requirements for the hose used in these assemblies into its own standard. SAE J2064 also provides the necessary values used in SAE J2727 Mobile Air-Conditioning System Refrigerant Emission charts for R-134a and R-1234yf. Mobile air-conditioning system refrigerant emissions rates are established in SAE J2727 Emission charts and are important.
2015-06-15
Technical Paper
2015-01-2249
Saad Bennouna, Said Naji, Olivier Cheriaux, Solene Moreau, Boureima Ouedraogo, Jean Michel Ville
Abstract Passengers' thermal comfort inside a car cabin is mainly provided by the Heating, Ventilation and Air Conditioning (HVAC) module. Air provided by HVAC is blown via a blower, passing through different components: flaps, thermal exchangers, ducts… and then distributed to car cabin areas. Interaction between airflow and HVAC components generates noises that emerge in car cabin. Due to this fact, noise is naturally created and its level is linked to flow rate. Valeo is aiming, though CEVAS project, to develop a prediction tool which will provide HVAC spectrum and sound quality data. This tool will be based, in particular, on aeroacoustic measurements using 2N-ports model and Particle Image Velocimetry methods to provide characteristics of HVAC components.
2015-06-15
Technical Paper
2015-01-2273
Curtis Jones, Zhengyu Liu, Suhas Venkatappa, James Hurd
Abstract This paper presents the methodology of predicting vehicle level automotive air-handling system air-rush noise sound quality (SQ) using the sub-system level measurement. Measurement setup in both vehicle level and sub-system levels are described. To assess the air-rush noise SQ, both 1/3 octave band sound pressure level (SPL) and overall Zwicker's loudness are used. The “Sound Quality Correlation Functions (SQCF)” between sub-system level and vehicle level are developed for the specified climate control modes and vehicle segment defined by J.D. Power & Associates, while the Zwicker's loudness is calculated using the un-weighted predicted 1/3 octave band SPL. The predicting models are demonstrated in very good agreement with the measured data. The methodology is applied to the development of sub-system SQ requirement for upfront delivery of the optimum design to meet global customer satisfaction
2015-06-15
Journal Article
2015-01-2276
Zhengyu Liu, Donald Wozniak, Manfred Koberstein, Curtis Jones, Jan Xu, Suhas Venkatappa
Abstract Refrigerant flow-induced gurgling noise is perceived in automotive refrigerant systems. In this study, the condition of the gurgling generation is investigated at the vehicle level and the fundamental root cause is identified as the two-phase refrigerant flow entering the TXV for system equipped with variable displacement compressors. By conducting literature reviews, the acoustic characteristics of the flow patterns and the parameters affecting the flow regimes in horizontal and vertical tubes are summarized. Then the gurgling mechanism is explained as the intermittent flow is developed at the evaporator inlet. In the end, the improved and feasible design for avoiding the intermittent flow (slug, plug or churn flow) or minimizing its formation is proposed and verified in refrigerant subsystem (RSS) level. Finally, the guidelines for the attenuation and suppression of the gurgle are provided.
2015-06-15
Journal Article
2015-01-2275
Manfred Koberstein, Zhengyu Liu, Curtis Jones, Suhas Venkatappa
Abstract In the thermal expansion valve (TXV) refrigerant system, transient high-pitched whistle around 6.18 kHz is often perceived following air-conditioning (A/C) compressor engagements when driving at higher vehicle speed or during vehicle acceleration, especially when system equipped with the high-efficiency compressor or variable displacement compressor. The objectives of this paper are to conduct the noise source identification, investigate the key factors affecting the whistle excitation, and understand the mechanism of the whistle generation. The mechanism is hypothesized that the whistle is generated from the flow/acoustic excitation of the turbulent flow past the shallow cavity, reinforced by the acoustic/structural coupling between the tube structural and the transverse acoustic modes, and then transmitted to evaporator. To verify the mechanism, the transverse acoustic mode frequency is calculated and it is coincided to the one from measurement.
2015-06-15
Journal Article
2015-01-2323
Abdelhakim Aissaoui, Ravindra S Tupake, Vilas Bijwe, Mohammed Meskine, Franck Perot, Alain Belanger, Rohit J Vaidya
For the automotive industry, acoustic comfort is of increasing importance. The market and customer expectation make the HVAC system noise quality a question to be addressed as early as possible in the vehicle development process. On one hand, the so-called traditional sources of annoyance such as engine, road-tires contact, exhaust systems and wind-noise have been significantly reduced for most traditional combustion engine vehicles. On the other hand, considered in the past as secondary noise sources, HVAC systems become the main sources for hybrid and electric and Stop-start vehicles. Previous studies have demonstrated the ability of a CFD/CAA approach based on the Lattice Boltzmann Method (LBM) to predict HVAC system noise including real and complex ducts, registers, mixing unit and blower geometries.
2015-06-10
WIP Standard
J2914
This document provides an overview on how and why EGR coolers are utilized, defines commonly used nomenclature, discusses design issues and trade-offs, and identifies common failure modes. The reintroduction of exhaust gas into the combustion chamber is just one component of the emission control strategy for internal combustion (IC) engines, both diesel and gasoline, and is useful in reducing exhaust port emission of Nitrogen Oxides (NOx). Other means of reducing NOx exhaust port emissions are briefly mentioned, but beyond the scope of this document.
2015-06-02
Standard
AIR1069B
Determine the required minimum oxygen concentration to be breathed prior to, during, and after a loss of cabin pressurization, and determine recommended means necessary to provide the required oxygen concentrations.
2015-05-29
Standard
ARP986D
This SAE Aerospace Recommended Practice (ARP) defines recommended analysis and test procedures for qualification of pneumatically, electrically, manually, and hydraulically actuated air valves. They may be further defined as valves that function in response to externally applied forces or in response to variations in upstream and/or downstream duct air conditions in order to maintain a calibrated duct air condition (e.g., air flow, air pressure, air temperature, air pressure ratio, or air shutoff). Qualification testing performed on the airplane to verify compatibility of the valve function and stability as part of a complete system is outside the scope of this document. Refer to ARP1270 for design and certification requirements for cabin pressurization control system components. As this document is only a guide, it does not supersede or relieve any requirements contained in detailed Customer specifications.
2015-05-07
Standard
J2842_201505
The intent of this standard is to establish a framework to assure that all evaporators for R-744, R-1234yf, and R-445A mobile air conditioning (MAC) systems meet appropriate testing and labeling requirements. SAE J639 requires vehicle manufacturers to perform assessments to minimize reasonable risks in production MAC systems. The evaporator (as designed and manufactured) shall be part of that risk assessment and it is the responsibility of the vehicle manufacturer to assure all relevant aspects of the evaporator are included. It is the responsibility of all vehicle or evaporator manufacturers to comply with the standards of this document at a minimum. (Substitution of specific test procedures by vehicle manufactures that correlate well to field return data is acceptable.) As appropriate, this standard can be used as a guide to support risk assessments.
2015-05-01
Journal Article
2015-01-9017
Johannes Wurm, Matthias Fitl, Michael Gumpesberger, Esa Väisänen, Christoph Hochenauer
Abstract Nowadays, investigating underhood airflow by using numerical simulation is a standard task in the development process of passenger cars and commercial vehicles. Numerous publications exist which deal with simulating the airflow through the engine compartment of road vehicles. However, hardly anything can be found which deals with off-road vehicles and nothing exists which focuses on snowmobiles. In the presented paper the airflow and the thermal conditions inside the engine compartment of a snowmobile are investigated by the usage of computational fluid dynamics (CFD) as well as experimental methods. Field tests at arctic conditions have been conducted on a serial snowmobile to measure temperatures inside the compartment and to gain realistic boundary conditions for the numerical simulation. Thermocouples (type K) were attached under the hood to measure exhaust, air, coolant and surface temperatures of several components at previously defined load cases.
2015-05-01
Magazine
Unmanned Aerial Systems Deploying Next-Generation UAS Platforms with 3U VPX Unmanned Ground Vehicles UGVs - On the Cutting Edge of Thermal Management Unmanned Surface/Underwater Vehicles Controlling the Seas - Introducing a New Concept in Autonomous Surface/Underwater Vehicles Robotics Connectivity in Robotic Systems
2015-04-23
WIP Standard
J3096
This SAE Recommended Practice is being developed primarily for passenger car and truck application, but may be used in marine, industrial, and similar applications.
2015-04-21
Standard
J51_201504
This SAE Standard covers reinforced hose, or hose assemblies, intended for conducting liquid and gaseous dichlorodifluoromethane (refrigerant 12) in automotive air-conditioning systems. The hose shall be designed to minimize permeation of refrigerant 12 and contamination of the system and to be serviceable over a temperature range of -30 to 120 °C (-22 to 248 °F). Specific construction details are to be agreed upon between user and supplier. NOTE— SAE J2064 is the Standard for refrigerant 134a hose. For refrigerant 134a use, refer to SAE J2064
2015-04-14
Collection
Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance and quality of climate control are both critical to customer satisfaction. The system has strong design interaction with other vehicle systems, while its primary objective is to deliver thermal comfort and occupant safety with low energy consumption. Localized Comfort, Secondary Fluids, Air Quality, Controls, System Sizing and HVAC consumer interface are just a few of the recent advances.
2015-04-14
Collection
This technical paper collection focuses on state of the art simulation technologies for modeling thermal systems and their application in the development and optimization of vehicle thermal management and fuel economy. The papers in this collection will range from empirical, 1D modeling methods to three dimensional CFD models as well as coupled methods.
2015-04-14
Collection
Proper thermal management can significantly contribute to overall system energy efficiency. This technical paper collection highlights the latest developments in thermal management energy efficiency.
2015-04-14
Collection
This technical paper collection considers modeling (zero-D, 1D, 2D, 3D CFD) and experimental papers on: combustion chamber, systems (lubrication, cooling, fuel, EGR); components (oil pumps, coolant pump, fuel injectors, compressors, turbines, turbochargers, torque converters, gear box, fans, bearings, valves, ports, manifolds, turbine housing); heat exchangers (radiators, oil coolers); aftertreatment (SCR, DOC, DOF, exhaust gas cooling); battery cooling (HEV, EV, motor/generator) and controls (passive and active).
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