Abstract Due to the increasing power density of onboard electric and electronic equipment and heat dissipation in civil and military aircraft, more efficient ways of transferring heat and new cooling techniques are necessary. A passive heat transfer prototype was developed and experimentally evaluated in laboratory and on ground and flight tests in an Embraer 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 electric 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 test, laboratory tests were conducted simulating ground and flight operations.
Integrated Power and Thermal Management System (IPTMS) Demonstration Including Preliminary Results of Rapid Dynamic Loading and Load Shedding at High Power
Abstract An IPTMS hardware facility has been established in the laboratories of the Aerospace Systems Directorate of the Air Force Research Laboratory (AFRL) at Wright-Paterson Air Force Base (WPAFB). This hardware capability was established to analyze the transient behavior of a high power Electrical Power System (EPS) coupled virtually to a Thermal Management System (TMS) under fast dynamic loading conditions. 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. This paper summarizes the IPTMS laboratory demonstration system, its capabilities, and preliminary test results.
Abstract Aircraft cabin systems, especially cabin management systems (CMS) have to cope with frequent cabin changes during their lifecycle. This includes not only layout rearrangements and technological upgrades during the service, but also extensive CMS customizations and product variations before aircraft delivery. Therefore it is inevitable for the CMS to be highly changeable and offer an easy and agile change process. Today's CMS solutions face this challenge with configurable system architectures. Although such architectures offer a vast change domain, they usually come with time consuming and error prone change processes. This paper introduces an adaptive avionics software architecture that enables the CMS to cope with cabin changes highly automatically and with minimal human interactions. The adaptation is performed during an on ground organization phase, in which system changes are detected and evaluated by the CMS itself.
Laboratory Testing of Vehicle and Industrial Heat Exchangers for Heat Transfer and Pressure Drop Performance
This SAE Recommended Practice is applicable to all heat exchangers used in vehicle and industrial cooling systems. This document outlines the tests to determine the heat transfer and pressure drop performance under specified conditions. This document has been reviewed and revised by adding several clarifying statements to Section 4.
This AIR is arranged in the following two sections: 2E - thermodynamic characteristics of working fluids, which contains thermodynamic diagrams for a number of working fluids currently in use and supplied by various industrial firms; and 2F - properties of heat transfer fluids, which contains data, primarily in graphical form, on fluids that are frequently used in fluid heat transfer loops. Other properties of the environment, gases, liquids, and solids, can be found, as follows, in AIR 1168/9: 2A-Properties of the natural environment; 2B-Properties of gases; 2C-Properties of liquids and 2D- Properties of solids.
In the last two decades engine research has been mainly focused on reducing pollutant emissions. This fact together with growing awareness about the impacts of climate change are leading to an increase in the importance of thermal efficiency over other criteria in the design of internal combustion engines (ICE). In this framework, the heat transfer to the combustion chamber walls can be considered as one of the main sources of indicated efficiency diminution. In particular, in modern direct-injection diesel engines, the radiation emission from soot particles can constitute a significant component of the efficiency losses. Thus, the main of objective of the current research was to evaluate the amount of energy lost to soot radiation relative to the input fuel chemical energy during the combustion event under several representative engine loads and speeds. Moreover, the current research characterized the impact of different engine operating conditions on radiation heat transfer.
Evaluation of Fuel Economy Potential of an Active Grille Shutter by the Means of Model Based Development Including Vehicle Heat Management
Abstract In the automotive field, reducing harmful pollutant, CO2 emissions and fuel consumption of vehicles while increasing customer comfort is a continuous challenge that requires more and more sophisticated technology implementations. However, it is often difficult to anticipate the advantages and drawbacks of a technology without having its prototype parts and/or knowing the optimal control strategy. In order to meet these challenges, the authors have developed a vehicle thermal model in AMESim platform to evaluate the benefits of an Active Grille Shutter (AGS) on fuel economy when applied. The vehicle model was based on a C-Segment vehicle powered by a 1.4L Diesel engine. The complete oil and coolant circuits were modeled as well as a friction model based on engine coolant and oil temperature.
The focus on engine thermal management is rapidly increasing due to the significant effect of heat losses on fuel consumption, engine performance and emissions. This work presents a time resolved, high resolution 3D engine heat balance model, including all relevant components. Notably, the model calculates the conjugated heat transfer between the solid engine components, the coolant and the oil. Both coolant and oil circuits are simultaneously resolved with a CFD solver in the same finite volume model as the entire engine solid parts. The model includes external convection and radiation. The necessary boundary conditions of the thermodynamic cycle (gas side) are mapped from a calibrated 1D gas exchange model of the same engine. The boundary conditions for the coolant and at the oil circuits are estimated with 1D models of the systems. The model is calibrated and verified with measurement data from the same engine as modeled.
To define a test standard for the measurement of efficiency and a usage-weighted evaluation for the purpose of reporting to EPA for emissions credits.
In this study, the effect of the low octane number fuel on HCCI engine performance was experimentally investigated using a slightly modified commercial four-cylinder gasoline engine. To operate the engine in HCCI strategy with wide operational range, the blowdwon supercharging (BDSC) system proposed by the authors was applied in the test engine. Research octane number (RON) of test fuels was varied from 90 to 78.5 as an experimental parameter. Experimental results showed that in the range of the present study, HCCI operational range, brake thermal efficiency and exhaust emissions during HCCI operation were little affected by the RON of the test fuels. In contrast, during SI operation, thermal efficiency was deteriorated with lower RON fuel because of knocking.
Impingement of a spray flame on the periphery of the piston cavity strongly affects heat loss to the wall. The heat release rate history is also closely correlated with the indicated thermal efficiency. For further thermal efficiency improvement, it is thus necessary to understand such phenomena in state of the art diesel engines, by observation of the actual behavior of an impinging spray flame and measurement of the local temperature and flow velocity. A top-view optically accessible engine system, for which flame impingement to the cavity wall can be observed from the top (vertically), was equipped with a high speed digital camera for direct observation. Once the flame impinged on the wall, flame tip temperature decreased roughly 100K, compared to the temperature before impingement.
Influences of Turbulence Scale on Development of Spherically Propagating Flame under High EGR Conditions
EGR (Exhaust gas recirculation) can reduce the pumping loss and improve the thermal efficiency of spark ignition engines. The techniques for combustion enhancement under high EGR rate condition has been required for further improvement of the thermal efficiency. In order to develop the technique of combustion enhancement by turbulence, the influences of turbulence scale on combustion properties, such as probability of flame propagation, EGR limit of flame propagation, flame quenching and combustion duration were investigated under the condition of same turbulence intensity. Experiments were carried out for stoichiometric spherically propagating turbulent i-C8H18/Air/N2 flames using a constant volume vessel. It was clarified that all of these combustion properties were affected by the turbulence scale. The development of spherically propagating turbulent flame during flame propagation was affected by the turbulence scale.
Thermodynamic and Optical Investigations on Particle Emissions in a DISI Engine at Boosted Operation
The subject of this paper is the reduction of the particle number emissions of a gasoline DI engine at high engine load (1.4 MPa IMEP). To reduce the particle number emissions, several parameters are investigated: the large scale charge motion (baseline configuration, tumble and swirl) can be varied at the single cylinder engine by using inlays in the intake port. The amount of residual gas can be influenced by the exhaust backpressure. By using a throttle valve, the exhaust backpressure can be set equal to the intake pressure and hence simulate a turbocharger's turbine in the exhaust system or the throttle valve can be wide open and thus simulate an engine using a supercharger. Additionally, higher fuel injection pressure can help to enhance mixture formation and thus decrease particulate formation. Therefore, a solenoid injector with a maximum pressure of 30 MPa is used in this work.
Numerical Investigation of a Potential of Dedicated EGR System for Increasing Thermal Efficiency of SI Engines Fueled with Methane and Propane
This study tried to find a potential of dedicated EGR (d-EGR) system added to the four-cylinder spark ignition (SI) engine to decrease heat loss (Qheatloss) and improve thermal efficiency (ηth). Test fuels were chosen by methane and propane. PREMIX code in CHEMKIN-PRO was employed to calculate laminar burning velocity (SL) and flame temperature (Tf). Wiebe function and Wocshni's heat transfer coefficient were considered to calculate ηth. The results show that the d-EGR system increased ηth and it was higher than that of stoichiometric combustion of conventional SI engines due to the low Tf and fast SL.
Numerical Optimization of Parameters to Improve Thermal Efficiency of a Spark-Ignited Natural Gas Engine
Natural gas is a promising alternative fuel for internal combustion engines because of its clean combustion characteristics and abundant reserves. However, it has several disadvantages due to its low energy density and low thermal efficiency at low loads. Thus, to assist efforts to improve the thermal efficiency of spark-ignited (SI) engines operating on natural gas and to minimize test procedures, a numerical simulation model was developed to predict and optimize the performance of a turbocharged test engine, considering flame propagation, occurrence of knock and ignition timing. The numerical results correlate well with empirical data, and show that increasing compression ratios and retarding the intake valve closing (IVC) timing relative to selected baseline conditions could effectively improve thermal efficiency. In addition, employing moderate EGR ratios is also effective for avoiding knock.
To correspond to the social requirements such as energy security, and climate change, enhancing engine thermal efficiency is strongly required in these days. As for the specific engine technologies to improve engine thermal efficiency, Atkinson cycle, cooled EGR (Exhaust Gas Recirculation), and low friction technologies have been developed [1, 2, 3, 4]. As a result, the current maximum thermal efficiency comes close to 40%. However, since it is considered that much higher engine thermal efficiency is required in the future to meet more stringent social requirements, a new prototype L4 engine which features a long stroke design with a high tumble is investigated to clarify the future direction in this paper. In regard to combustion, the lean boosted concept with cooled EGR is examined. In consequence, it is shown that more than 45% engine thermal efficiency can be achieved. This paper describes the means to enhance engine thermal efficiency and a future possibility.
Analysis of Thermal Efficiency Improvement of a Highly Boosted, High Compression Ratio, Direct-Injection Gasoline Engine with LIVC and EIVC at Partial and Full Loads
The improvement mechanism of fuel consumption at partial and full loads of a boosted direction-injection gasoline engine with the elevated geometrical compression ratio and Miller cycle by either early or late intake valve closing (EIVC or LIVC) are analyzed based on the first law of thermodynamics and one dimensional engine simulation. An increase in geometric compression ratio increases the theoretical thermal efficiency for all the operating loads, but deteriorates the fuel economy at full loads, owing primarily to the full-load knock limit. Use of Miller cycle improves the fuel economy for both the partial and full load operations by reducing the pumping loss and optimizing the combustion phasing, respectively. A comparison between EIVC and LIVC on the influencing factors on the thermal efficiency at the partial load shows that EIVC leads to higher mechanical efficiency and less heat transfer loss than LIVC, and hence its efficiency improvement is superior over LIVC.
This SAE Aerospace Recommended Practice (ARP) covers procedures or methods to be used for fabricating, handling, testing, and installation of oxygen lines in an aircraft oxygen system.
This document presents minimum criteria for the design and installation of LED passenger reading light assemblies in commercial aircraft. The use of “shall” in this specification expresses provisions that are binding. Non-mandatory provisions use the term “should.”
The Scope of SAE J2064 covers coupled hose assemblies intended for containing and circulating lubricant, liquid and gaseous R134a and/or R-1234yf refrigerant in automotive air-conditioning systems. Historically, requirements for the hose used in coupled automotive refrigerant air conditioning assemblies was included in SAE J2064. SAE J2064 has been changed to establish the requirements for factory and field coupled hose assemblies. SAE J3062 has been issued to define 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. The certified coupling of MAC hose assemblies is required in meeting certain regulatory requirements. A hose which has met the requirements of SAE J3062 and certified in J2911 must be used as part of the coupled assembly.
This SAE Aerospace Standard (AS) specifies minimum performance standards for all types of Electronic Displays and Electronic Display Systems that are intended for use in the flight deck by the flightcrew in all 14 CFR Part 23, 25, 27, and 29 aircraft. The requirements and recommendations in this document are intended to apply to all installed electronic displays and electronic display systems within the flight deck, regardless of intended function, criticality, or location within the flight deck, but may also be used for non-installed electronic displays. This document provides baseline requirements and recommendations (see section 2.3 for definitions of “shall” and “should”). This document primarily addresses hardware requirements, such as electrical, mechanical, optical, and environmental. It does not address system specific functions.
This Information Report provides recommendations for alphanumeric messages that are supplied to the vehicle by external (e.g., RDS, satellite radio) or internal (e.g., infotainment system) sources while the vehicle is in-motion. Information/design recommendations contained in this report apply to OEM (embedded) and aftermarket systems. Ergonomic issues with regard to display characteristics (e.g., viewing angle, brightness, contrast, font design, etc.) should review ISO 15008.
Performance Standard for Seats in Civil Rotorcraft, Transport Aircraft, and General Aviation Aircraft
This SAE Aerospace Standard (AS) defines minimum performance standards, qualification requirements, and minimum documentation requirements for passenger and crew seats in civil rotorcraft, transport aircraft, and general aviation aircraft. The goal is to achieve comfort, durability, and occupant protection under normal operational loads and to define test and evaluation criteria to demonstrate occupant protection when a seat/occupant/restraint system is subjected to statically applied ultimate loads and to dynamic impact test conditions set forth in the applicable Federal Regulations 14 CFR 23, 25, 27, or 29. Guidance for test procedures, measurements, equipment, and interpretation of results is also presented to promote uniform techniques and to achieve acceptable data. While this document addresses system performance, responsibility for the seating system is divided between the seat supplier and the installation applicant.
Accelerated Exposure of Automotive Interior Trim Components Using a Controlled Irradiance Xenon-Arc Apparatus
This test method specifies the operating procedures for a controlled irradiance, xenon arc apparatus used for the accelerated exposure of various automotive interior trim components. Test duration as well as any exceptions to the specimen preparation and performance evaluation procedures contained in this document, are covered in material specifications of the different automotive manufacturers. Any deviation to this test method, such as filter combinations, is to be agreed upon by contractual parties.
Chipping in to get more from battery packs Power semiconductors help extend range, keeping their cool while improving efficiency at higher voltages.
This SAE Aerospace Standard (AS) specifies minimum performance standards for airborne binocular Head-Up Displays (HUDs) in fixed wing (14 CFR part 23, 25) aircraft; while this document is also applicable to rotorcraft (14 CFR part 27, 29) additional performance standards may be required for rotorcraft. This aerospace standard covers basic display standards, but does not include specific application requirements. Specific applications can include flight instrumentation, navigation, engine and system status, alerting, surveillance, communication, terrain awareness, weather, enhanced vision, synthetic vision and other displays. This document covers criteria for conformal and non-conformal HUD systems that are intended for use in the flight deck by the pilot or copilot. Display minimum performance characteristics are specified for standard and other environmental conditions for the purpose of product qualification.
Based in Frankfurt, Pierre Juan manages sales and technical teams across 19 countries as the Global Automotive Vice President at Styrolution. The company describes itself as the leading global styrenics supplier. He discusses the future of plastics in the automotive industry, including opportunities and challenges.
This SAE Aerospace Recommended Practice (ARP) documents a common understanding of terms, compliance issues and design criteria to facilitate certification of seat installations specific to Part 25 aircraft. This ARP provides general guidance for seats to be installed in Part 23 aircraft and Parts 27 and 29 rotorcraft and does not specify specific designs or design methods for such certification.
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.
Automotive Refrigerant Recovery/Recycling/Recharging Equipment Intended for use with Both R-1234yf and R-134a
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.