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2017-10-08
Technical Paper
2017-01-2442
Bingqing Xiao, Wei Wu, Jibin Hu, Shihua Yuan, Chenhui Hu
The prediction of temperature distribution and variation of oil-cooled sliding disk pair is essential for the design of wet clutches and brakes in vehicle transmission system. A heat transfer model is established in the study and some fluid-solid coupled heat transfer simulations are performed to investigate the thermal behaviors of wet clutch during sliding. Both cooling liquid and grooved solid disks are contained in the heat transfer model and the heat convection due to the cooling liquid in the radial grooves is also considered by fluid-solid coupled transient heat transfer simulations. The temperature distribution and variation of the grooved disk are discussed and analyzed in detail. The results indicate that the temperature distribution on the grooved disk is nonuniform. The temperature within the middle radius area is higher than that in the inner and outer radius area. The outer radius temperature is higher than the inner radius temperature at the contact face.
2017-09-23
Technical Paper
2017-01-1984
Jun Ma, Junyi Li, Zaiyan Gong, Jihong Yu
Given the wide adoption of touchscreens in vehicles, an interesting debate is taking place regarding the good screen size, length-width ratio and whether the usability of in-vehicle information system (IVIS) would be decreased by a larger screen, especially. Moreover, the lack of scientific evidence about the concrete impact of touch screen size on usability raises questions to practitioners. In this paper, we investigated the impact of in-vehicle touch screen size on users' visual behavior and usability as measured using eye tracker and questionnaire. Two experiments were conducted on 30 participants. In the first experiment, participants were asked to seek same information on four different in-vehicle screens based on simulated driving environment, while eye movement was recorded for analyzing efficiency of visual behavior.
2017-09-19
Technical Paper
2017-01-2038
Russell H. Strehlow
A Vapor Envelope is an ultra-thin walled vapor chamber that enables a unique combination of lighter weight, lower profile, and lower cost for heat spreading or heat removal applications. It evolved from work done as part of a DARPA program on Thermal Ground Planes. This paper examines a published testing protocol for the measurement of the thermal resistance of thin flexible thermal ground planes. It then applies an adapted version of the published technique to measure the thermal resistance of a vapor envelope and a dimensionally equivalent solid copper heat spreader. Finally, it looks at the implications of a significantly lower thermal resistance for a specific configuration.
2017-09-19
Technical Paper
2017-01-2157
Susan Michaelis
There are certification and airworthiness requirements related to the provision of clean crew and passenger compartment breathing air utilizing the aircraft bleed air system. There have been continuing reports and studies over the years regarding oil fumes in aircraft, including impaired crew performance. Oil fumes are viewed in varying ways ranging from rare seal bearing failures, to low-level leakage in normal flight. MSc research was undertaken to assess whether there is any gap between the certification requirements for the provision of clean air in crew and passenger compartments and the theoretical and practical implementation of the requirements using the bleed air system. A comprehensive literature search reviewed applicable certification standards and the documented and theoretical understanding of oil leakage. 2 types of Interviews were undertaken to address the research questions.
2017-09-19
Technical Paper
2017-01-2037
Daniel Schlabe, Dirk Zimmer, Alexander Pollok
The thermal inertia of aircraft cabins and galleys is significant for commercial aircraft. The aircraft cabin is controlled by the Environment Control System (ECS) to reach, among other targets, a prescribed temperature. Allowing a temperature band of e.g. 2 K around the prescribed temperature, it is possible to use the cabin dynamics as an energy storage. This storage can then be used to reduce electrical peak power, increase efficiency of ECS, reduce thermal cooling peak power, or reduce engine offtake if it is costly or not sufficiently available. In the same way, also the aircraft galleys can be exploited. Since ECS and galleys are among the largest consumers of electrical power or bleed air, there is a large potential on improving energy efficiency or reducing system mass to reduce fuel consumption of aircraft. This paper investigates different exploitation strategies of cabin and galley dynamics using modelling and simulation.
2017-09-19
Technical Paper
2017-01-2039
Michael Sielemann, Changsoo Lee, Victor-Marie LeBrun, Chiwoo Ahn, Arnaud Colleoni, Dongkyu Lee, JeongSeok Lee, Anh Nguyen, Katrin Proelss, Hyon Min Yoon
Thermal management on aircraft has been an important discipline for several decades. However, with the recent generations of high performance aircraft, thermal management has evolved more and more into a critical performance and capability constraint on the whole aircraft level. Fuel continues to be the most important heat sink on high performance aircraft, and consequently the requirements on thermal models of fuel systems are expanding. As the scope of modeling and simulation is widened in general, it is not meaningful to introduce a new isolated modeling and simulation capability. Instead, thermal models must be derived from existing model assets, and eventually enable integration across several physical domains. This paper describes such an integrated approach based on the Modelica Fuel System Library and the 3DExperience Platform.
2017-09-19
Technical Paper
2017-01-2160
Ferdinand Spek, Maarten Weehuizen, Ilja Achterberg
In new aircraft programs, systems’ functionality is increasingly becoming integrated into modular avionics. Controllers may not be delivered by the systems supplier so this trend creates a new interface between systems and controllers. A functional software specification is therefore needed to facilitate the building of the software by the controller supplier. In the case of an ECS system controller, the hardware was obtained from different suppliers and a software functional specification was needed for the controller supplier. To be able to design and verify the system functionality, an integrated ECS simulation model was created which coupled the thermodynamics of the aircraft and ECS system to the controller actions. The model also included functionality to simulate sensor noise and component failures. The thermodynamic model was created in Matlab/Simulink and consisted of a combination of direct programming as well as data on a Flowmaster model for the bleed system.
2017-09-19
Technical Paper
2017-01-2161
Alexander J. Pollok
For thermal cabin control of commercial aircraft, the cabin is usually divided into a small number of temperature zones. Each zone features its own air supply pipe. The necessary installation space for ducting increases significantly with the number of zones. This requires the number of temperature zones to be low. Factors such as seating layout, galley placement and passenger density result in deviations in heat flux throughout the cabin. These deviations cannot be compensated by the control system, if they occur within the same temperature zone. This work presents a novel temperature regulation concept based on local mixing. In this concept, two main ducts span the complete cabin length, and provide moderately warm and cold air. At each temperature zone, cabin supply air is locally mixed using butterfly valves. In this way, the number of temperature zones can be individually scaled up without any additional ducting, only requiring additional valves for each temperature zone.
2017-09-17
Technical Paper
2017-01-2500
Bo Huang, Longjie Xiao
Head-up Display (HUD) system can avoid divers’ distraction on dashboard and effectively reduce collisions caused by emergency events, which is gradually being realized by researchers around the world. However, the current HUD only displays information like speed, fuel consumption, other information like acceleration and braking can’t be displayed yet. This research will uses the color and position change of the indicator symbol to remind drivers of braking information like braking time, braking severity, which can alert drivers to make braking operations timely and accurately. The system has the advantages of safe, intuition and real-time. The vehicle safety speed is calculated according to the road parameters like adhesion coefficient, slope and curvature as well as vehicle parameters like vehicle mass and centroid. And then the appropriate braking operations like braking time are obtained by combining the vehicle status like speed and steering.
2017-09-04
Technical Paper
2017-24-0032
Gilles Decan, Stijn Broekaert, Tommaso Lucchini, Gianluca D'Errico, Jan Vierendeels, Sebastian Verhelst
The present work details a study of the heat flux through the walls of an internal combustion engine. The determination of this heat flux is an important aspect in engine optimization, as it influences the power, efficiency and the emissions of the engine. Therefore, a set of simulation tools in the OpenFOAM® software has been developed, that allows the calculation of the heat transfer through engine walls for ICEs. Normal practice in these types of engine simulations is to apply a wall function model to calculate the heat flux, rather than resolving the complete thermo-viscous boundary layer, and perform simulations of the closed engine cycle. When dealing with a complex engine, this methodology will reduce the overall computational cost. It however increases the need to rely on assumptions on both the initial flow field and the behavior in the near-wall region.
2017-09-04
Journal Article
2017-24-0041
Daniele Piazzullo, Michela Costa, Luigi Allocca, Alessandro Montanaro, Vittorio ROCCO
In gasoline direct injection (GDI) engines, dynamics of the possible spray-wall interaction are key factors affecting the air-fuel mixture distribution and equivalence ratio at spark timing, hence influencing the development of combustion and the pollutants formation at the exhaust. Gasoline droplets impact may rebound with consequent secondary atomization or deposit in the liquid phase over walls as a wallfilm. This last slowly evaporate with respect to free droplets, leading to local enrichment of the mixture, hence to increased unburned hydrocarbons and particulate matter emissions. In this scenario, complex phenomena characterize the turbulent multi-phase system where heat transfer involves the gaseous mixture (made of air and gasoline vapour), the liquid phase (droplets not yet evaporated and wallfilm) and the solid wall, especially in the so-called wall-guided mixture formation mode.
2017-09-04
Technical Paper
2017-24-0076
Mark A. Hoffman, Ryan O'Donnell, Zoran Filipi
The proven impact of combustion chamber deposits on advanced compression ignition combustion strategies has steered recent works toward the development of thermal barrier coatings, which can mimic their benefits on combustion efficiency and operational range expansion. However, recent work based on statistical thermodynamics has indicated that inter-molecular radiation during the combustion event may subject the combustion chamber walls to non-negligible radiation heat transfer, regardless of the relatively low soot formation within the well-mixed and lean charge. In the present paper, the impact of radiation heat transfer on combustion chamber deposits and thermal barrier coatings is studied. The morphological construction of the combustion chamber deposit layer is shown to be partially transparent to radiation heat transfer, drawing corollaries with ceramic based thermal barrier coatings.
2017-09-04
Technical Paper
2017-24-0158
Teresa Castiglione, Giuseppe Franzè, Angelo Algieri, Pietropaolo Morrone, Sergio Bova
The paper shows how specific requirements of the cooling system of an ICE can be met by actuating the coolant flow rate independently of engine speed, by means of an electric pump and of an ad-hoc developed control system. Given that the proposed methodology is valid for each condition, in the present paper the focus is on the engine operating under fully warmed conditions, with the aim to keep the wall temperature into the prescribed limits, with the lowest possible coolant flow rates. This goal is achieved by properly defining the controller parameters. The developed controller is based on the Robust Model Predictive Control approach, which makes use of a lumped parameter model of the engine cooling system. The model also includes the radiator-thermostatic valve-fan block and incorporates the nucleate boiling heat transfer regime.
2017-09-04
Journal Article
2017-24-0161
Noboru Uchida, Hideaki Osada
It can’t be avoided reducing heat loss from in-cylinder wall for further improvement in brake thermal efficiency (BTE). Especially for diesel engines, spray flame interference on the cavity and piston top wall during combustion period could be a major cause of the heat loss. To reduce heat transfer between hot gas and cavity wall, thin Zirconia layer (0.5mm) on the cavity surface of the forged steel piston was firstly formed by thermal spray coating aiming higher surface temperature swing precisely synchronized with flame temperature near the wall resulting in the reduction of temperature difference. However, no apparent difference in the heat loss was observed. On the contrary, BTE was deteriorated by the increase in other energy losses. To find out the reason why heat loss was not so improved, direct observation of flame impingement to the cavity wall was carried out with the top view visualization technique, for which one of the exhaust valves was modified to a sapphire window.
2017-09-04
Technical Paper
2017-24-0107
Alessandro Montanaro, Luigi Allocca, Vittorio Rocco, Michela Costa, Daniele Piazzullo
Abstract Gasoline direct injection (GDI) engines are characterized by complex phenomena involving spray dynamics and possible spray-wall interaction. Control of mixture formation is indeed fundamental to achieve the desired equivalence ratio of the mixture, especially at the spark plug location at the time of ignition. Droplet impact on the piston or liner surfaces has also to be considered, as this may lead to gasoline accumulation in the liquid form as wallfilm. Wallfilms more slowly evaporate than free droplets, thus leading to local enrichment of the charge, hence to a route to diffusive flames, increased unburned hydrocarbons formation and particulate matter emissions at the exhaust. Local heat transfer at the wall obviously changes if a wallfilm is present, and the subtraction of the latent heat of vaporization necessary for secondary phase change is also an issue deserving a special attention.
2017-09-04
Technical Paper
2017-24-0016
Morris Langwiesner, Christian Krueger, Sebastian Donath, Michael Bargende
Abstract The real cycle simulation is an important tool to predict the engine efficiency. To evaluate Extended Expansion SI-engines with a multi-link cranktrain, the challenge is to consider all concept specific effects as best as possible by using appropriate submodels. Due to the multi-link cranktrain, the choice of a suitable heat transfer model is of great importance since the cranktrain kinematics is changed. Therefore, the usage of the mean piston speed to calculate a heat-transfer-related velocity for heat transfer equations is not sufficient. The heat transfer equation according to Bargende combines for its calculation the actual piston speed with a simplified k-ε model. In this paper it is assessed, whether the Bargende model is valid for Extended Expansion engines. Therefore a single-cylinder engine is equipped with fast-response surface-thermocouples in the cylinder head. The surface heat flux is calculated by solving the unsteady heat conduction equation.
2017-09-04
Journal Article
2017-24-0021
Sabino Caputo, Federico Millo, Giancarlo Cifali, Francesco Concetto Pesce
Abstract One of the key technologies for the improvement of the diesel engine thermal efficiency is the reduction of the engine heat transfer through the thermal insulation of the combustion chamber. This paper presents a numerical investigation on the effects of the combustion chamber insulation on the heat transfer, thermal efficiency and exhaust temperatures of a 1.6 l passenger car, turbo-charged diesel engine. First, the complete insulation of the engine components, like pistons, liner, firedeck and valves, has been simulated. This analysis has showed that the piston is the component with the greatest potential for the in-cylinder heat transfer reduction and for Brake Specific Fuel Consumption (BSFC) reduction, followed by firedeck, liner and valves. Afterwards, the study has been focused on the impact of different piston Thermal Barrier Coatings (TBCs) on heat transfer, performance and wall temperatures.
2017-07-20
WIP Standard
ARP5873B
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.”
CURRENT
2017-07-19
Standard
ARP798B
This SAE Aerospace Recommended Practice (ARP) covers the general requirements and test procedures recommended for use with white incandescent integrally lighted instruments. Its use should provide uniformity of illumination from instrument to instrument and legibility under daylight operation. An appendix is provided to familiarize the designer with some of the techniques used to obtain uniformity of color and illumination in various types of instruments.
2017-07-14
Article
It is clear that as each new airplane design emerges, the trend toward more electrically powered systems is going to gain momentum. EPSs offer improved performance and reliability while saving weight.
2017-07-14
WIP Standard
J814

This SAE Information Report is a source of information concerning the basic properties of engine coolants which are satisfactory for use in internal combustion engines. Engine coolant concentrate (antifreeze) must provide adequate corrosion protection, lower the freezing point, and raise the boiling point of the engine coolant. For additional information on engine coolants see ASTM D 3306 and ASTM D 4985.

The values presented describe desirable basic properties. The results from laboratory tests are not conclusive, and it should be recognized that the final selection of satisfactory coolants can be proven only after a series of performance tests in vehicles.

The document describes in general the necessary maintenance procedures for all engine coolants to insure proper performance as well as special requirements for coolants for heavy-duty engines.

This document does not cover maintenance of engine cooling system component parts.

CURRENT
2017-07-13
Standard
J1717_201707
SAE J1717 is an advisory document suggesting minimum recommended testing, appearance evaluation, and protocol for specifying the recommendations with regard to Singular Unassembled Automotive Interior Trim Parts.
2017-07-12
WIP Standard
J759
This SAE Recommended Practice provides the lighting function identification codes for use on all passenger vehicles, trucks, trailers, motorcycles, and emergency vehicles.
2017-07-10
WIP Standard
J3151
This document defines key terms and concepts for relating effects of driver distraction on driving performance, physiological indicators, subjective assessments, or combinations thereof to effects of driver distraction on crash involvement. These concepts are intended to contribute to methodologies for assessing driver distraction metrics in terms of their reliability, repeatability, bias, and predictive or descriptive validity and distraction evaluation procedures in terms of their real-world representativeness. The actual specification of such a methodology is outside the scope of the present document. While the focus is on driver distraction evaluation for technology evaluations and driver activities, the concepts described herein may be applicable also to other forms of driving performance evaluation. The intended users of the document are practitioners in the industry, academia and other organizations with an interest in driving performance assessment and road safety.
CURRENT
2017-07-10
Standard
J3109_201707
The intention of this standard is to establish a framework to measure the efficiency of PWM HVAC Blower Controllers and Brushless DC Motor Controllers and define a usage based overall efficiency. This result can then be used by vehicle OEMs to demonstrate compliance towards requirements or benchmarks established by regulatory agencies.
2017-07-10
Technical Paper
2017-28-1926
Jos Frank, Sohin Doshi, Manchi Rao, Prasath Raghavendran
Abstract In today’s automotive scenario, noise vibration and harshness (NVH) has become a synonym for quality perception. This paper evaluates the problem of vibration and noise experienced in M2 category 40 seat bus and suggests the counter measures. Severe vibration is experienced on the bus floor, predominantly towards rear part of the bus. Vibration along with acoustic boom occurs prominently in 4th gear wide open throttle operating condition between 1300-1600 rpm of the engine. This paper focuses on reducing NVH levels by working on the transfer path with little modifications on power-train. Preliminary torsional measurements conducted on powertrain indicated high torsional excitation in the driveline during the problematic rpm zone. Further, Operational Deflection Shape (ODS) analysis revealed that the transfer path to the cabin is rear differential unit and suspension links. The dominant frequencies were identified along the transfer path and suitable modifications were done.
2017-07-10
Technical Paper
2017-28-1924
Praveen Kumar, Vivek KV Shenoy, Nareen Kinthala, Srikanth Sudhir
Abstract Plenum is the part located between the front windshield and the bonnet of an automobile . It is primarily used as an air inlet to the HVAC during fresh air mode operation. It’s secondary functions include water drainage, aesthetic cover to hide the gap between windshield to bonnet, concealing wiper motors and mechanisms etc. The plenum consists mainly two sub parts viz. upper plenum and lower plenum. Conventional plenum design which is found in majority of global OEMs employ a plastic upper plenum and a metal lower plenum which spans across the entire width of engine compartment. This conventional lower plenum is bulky, consumes more packaging space and has more weight. In this paper, we propose a novel design for the plenum lower to overcome above mentioned limitations of the conventional design. This novel design employs a dry and wet box concept for its working and is made up of complete plastic material.
2017-07-10
Technical Paper
2017-28-1923
Satish Mudavath, Ganesh Dharmar, Shyam Somani
Abstract Digital human models (DHM) have greatly enhanced design for the automotive environment. The major advantage of the DHMs today is their ability to quickly test a broad range of the population within specific design parameters. The need to create expensive prototypes and run time consuming clinics can be significantly reduced. However, while the anthropometric databases within these models are comprehensive, the ability to position the manikin’s posture is limited and needs lot of optimization. This study enhances the occupant postures and their seating positions, in all instances the occupant was instructed to adjust to the vehicle parameters so they were in their most comfortable position. While all the Occupants are accommodated to their respective positions which finally can be stacked up for space assessments. This paper aims at simulating those scenarios for different percentiles / population which will further aid in decision making for critical parameters.
2017-07-10
Technical Paper
2017-28-1958
Jyothivel Giridharan, Gokul Kumar
Bio-fuels potentially represent a more environmentally friendly alternative to fossil fuels as they produce fewer greenhouse gas emissions when burned. Ethanol is one such bio-fuel alternative to the conventional fossil fuels. Towards the initiative of sustainable transportation using alternative fuels, it is attempted to develop an ethanol powered engine for commercial vehicles and this paper attempts to explain the 1D thermodynamic simulation carried out for predicting the engine performance and combustion characteristics, as a part of the engine development program. Engine simulation is becoming an increasingly important engineering tool for reducing the development cost and time and also helps in carrying out various DOE iterations which are rather difficult to be conducted experimentally in any internal combustion engine development program. AVL Boost software is used for modeling and simulation.
CURRENT
2017-07-10
Standard
J2765_201707
1.1 The impact of mobile air conditioning systems on the environment is becoming more important.
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