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2015-04-14
Technical Paper
2015-01-1394
Alessandro Naddeo, Marco Apicella, Davide Galluzzi
General comfort may be defined as the “level of well-being” perceived by humans in a working environment. The state-of-the-art about evaluation of comfort/discomfort shows the need for an objective method to evaluate the “effect in the internal body” and “perceived effects” in main systems of comfort perception. Some medical studies show that each human joint has its own natural Rest Posture (RP); in this Rest Posture human muscles are completely relaxed or at minimum strain level: when it happens the geometrical configuration corresponds to the natural position of resting Arms/Legs/Neck etc.. From this starting point, authors developed and build, through a wide experimental campaign, the postural-comfort curves for each DOF of human upper limbs joints; the obtained comfort curves are regular and don’t show any kind of discontinuity. A software named Ca-Man has been developed in order to analyze a general posture and calculate a postural comfort index for the entire upper body.
2015-04-14
Technical Paper
2015-01-1397
Donghee Lee, Younggeun OH
In recent years, trends are changed that a focus on the automotive seat comfort is from the initial and short-term seating feel into the long-term seating feel. However, there was no standardized test method for long-term seating comfort. The aim of this study is to identify a relationship between mechanical properties and stress of seats as one of the objective test methods for long-term evaluation. Totally, 18 samples were prepared with the four identifying factors - three levels of density, hardness and thickness of the PU foam pad, and two levels for stiffness of cushion suspension spring. It was conducted that four kinds of in-lab test and multi-dynamic driving test. Each two sort of static and dynamic comfort in-lab tests were performed to define differences and find relationships among each test samples. Three comfort experts were participated in this study to evaluate each test seats.
2015-04-14
Technical Paper
2015-01-1691
Manabu Matsumoto, Masayoshi Mori, Tomohide Haraguchi, Makoto Ohtani, Tomoya Kubo, Kanji Matsumoto, Hiroshi Matsuda
Exhaust heat recovery units that use a thermoelectric element generate electricity by creating a temperature difference in the thermoelectric element by heating one side and cooling the other side of the thermoelectric circuit (module). In this case, the typical structure does not directly join the thermoelectric module with the heat sink, and instead presses the thermoelectric module against the heat sink using bolts or other means in order to prevent thermoelectric element damage due to the difference in linear expansion between the cooled and heated sides of the thermoelectric module. However, this poses the issues associated with a complex, heavy and expensive structure. Therefore, a new vacuum space structure was devised that houses the thermoelectric module in a vacuum chamber and presses the module against the heat sink using atmospheric pressure.
2015-04-14
Technical Paper
2015-01-0359
Satoki Uematsu, Toshiyuki Uehara, Toshiya Uchida, Gursaran D. Mathur
In last 10 years or so, a number of OEMs are designing vehicles with start-stop function to save energy and to reduce pollution. For these systems, the situations in which air-conditioning systems are used have been changing with a significant increase in adoption of idle-time reduction systems (no idling-system). Blower fan remain operating at idle condition while compressor stops in most cases for these systems. In this case, the air temperature at the vent outlets is likely to increase. The increase in the air temperature under range of thermal boundary conditions around the evaporator causes a concern of odor to occur. This paper describes and explains experimental studies on changes in heat and humidity at the air outlets according to the switching operation of compressor and root cause analyses of odor coming from air-conditioning system for vehicles with start-stop function.
2015-04-14
Technical Paper
2015-01-1274
Prashant Kaliram Pradip, David S-K. Ting, Graham Reader
Otto cycle engine is one of the most common technology used in automotive industry to produce mechanical power from the chemical energy of the fuel. In the cyclic process, about one third of heat energy produced by combustion is rejected to the exhaust, this limits the efficiency of the engine. Stirling engine is a closed-cycle external combustion engine, which works on a temperature difference and converts the heat energy into mechanical work. It is one of the most efficient engine, which can be used to recover heat from the exhaust of Internal Combustion (IC) engine. This combined Otto and Stirling cycle will substantially increase the overall efficiency of the system. Thermodynamic analysis for the combined system with a primary IC engine to power transmission and a Stirling engine for additional power and efficiency is proposed. The study starts with the modelling of commercially available Otto cycle for engine performance.
2015-04-14
Technical Paper
2015-01-0343
Carlo N. Grimaldi, Claudio Poggiani, Alessandro Cimarello, Matteo De Cesare, Giovanni Osbat lng
The CO2 emission limits for vehicles are becoming more stringent with the aim of reducing greenhouse gas emissions and for improving fuel economy. The New European Driving Cycle (NEDC), adopted to measure all new internal combustion engine emissions in the European Union, is performed on cold vehicle, starting at a temperature of 22°C ± 2°C. So the cold-start efficiency of internal combustion engine is becoming of predominant interest. Since at the cold start the lubricant oil viscosity is higher than at target operating temperature, the consequently higher energy losses due to the friction losses can substantially affect the emission cycle result in terms of fuel consumption and CO2 emission. A suitable thermal management system, such as an exhaust-to-oil heat exchanger, could help to raise the oil temperature more quickly.
2015-04-14
Technical Paper
2015-01-1689
Xu Song, Ryan Fortier, Scott Sarnia
The underhood hot air recirculation greatly impacts A/C system performance at idle and low vehicle speed conditions. The hot air recirculation can raise condenser cooling airflow temperature over ambient by 18°C, which lowers condenser cooling capacity and increases compressor work. Underhood airflow research suggests that a properly designed air duct is able to minimize hot air recirculation and improve the Compressors Coefficient of Performance (COP) at idle by 27%. This paper discusses underhood hot air recirculation testing methods, airflow distribution, and air duct design concepts. This dedicated air duct design indicates it should improve A/C emissions, which could contribute to meeting the Environmental Protection Agency’s (EPA) Green House Gas Emissions Regulations in North America.
2015-04-14
Technical Paper
2015-01-0357
Huize Li, Predrag Hrnjak
This paper presents a method of utilizing infrared images to quantify the distribution of liquid refrigerant mass flow rate in microchannel heat exchangers, which are widely used in automobile air conditioning systems. In order to achieve quantification, a relationship is built between the liquid mass flow rate through each microchannel tube and the corresponding air side capacity calculated from the infrared measurement of the wall temperature. After being implemented in a heat exchanger model, the quantification method is validated against experimental data. This method can be used for several types of heat exchangers and it can be applied to various heat exchanger designs.
2015-04-14
Technical Paper
2015-01-0367
Zhiqiang Hu
The cabin temperature increases quickly and can reach 80℃ when the vehicle parks in the summer sunlight which has the bad influence on the occupants entering comfort. Most luxury vehicles reduce the internal temperature through opening air-condition in advance or using on-board battery to drive the cabin ventilator, which requires relatively complex control system and limits the system’s working time because of energy consumption. This research adopts the solar empennage as the ventilation power supply and accomplishes the cabin real-time heat rejection by achieving the steady air circulation for both inside and outside environment. First, the static thermal transfer model of the crew cabin is established. Then, on the basis of the parameters of the prototype ventilation pipe, the ventilation model for the outside circulation is built. After that, the parameters of the solar empennage are determined according to the control target of the cabin internal temperature.
2015-04-14
Technical Paper
2015-01-1608
Roberto Cipollone, Marco Mauriello, Davide Di Battista
Internal combustion engines are the most important source of propulsive energy in the transportation sector. The expectations of more efficient and performing engines have to match with environmental issues that lead to cleaner vehicles. In fact, the awareness of oil shortage and greenhouse effect has led international governments to impose energy consumption levels which reflects on CO2 emissions: this commitment adds to the emission targets (CO, HC, NOX, PM) which proceed continuously toward lower levels. All of these limits will provide a huge effort on engine and vehicle efficiency with non-negligible costs. CO2 reductions appears the most important issue and it is representing the technological future driver. A smart way match to fulfill the targets concerning CO2 emission is to recover energy usually wasted and re-use it for engine and vehicle needs.
2015-04-14
Technical Paper
2015-01-1658
Xi Luo, Xin Yu, Marcis Jansons
As engine efficiencies continue to rise, heat transfer losses increase in relative importance. Understanding of these phenomena requires accurate in-cylinder wall temperature measurements. A novel dual wavelength infrared diagnostic has been developed to measure in-cylinder surface temperatures with potential temporal resolutions exceeding 1ns. The diagnostic has the capability to measure low amplitude, high frequency temperature variations, such as those occurring during the gas exchange process. A dual wavelength ratio method has also been developed to correct for background scattering reflections. The assumption that scatting reflection effect is constant during an engine cycle has also been provided at all exam engine condition. In-cylinder surface temperatures have been simultaneously measured during motored engine conditions with three independent measurement techniques: thermocouple, laser-induced phosphorescence, and the dual wavelength infrared diagnostic.
2015-04-14
Technical Paper
2015-01-1651
Francisco Payri, Jaime Martin, Antonio Garcia, Ricardo Carreño
Determining the weight of different energy terms in a reciprocating engine is a key issue to evaluate the interest of improving a specific thermo-and-mechanical process and to assess the potential of different strategies to reduce the consumption. In this paper, the effect of some parameters variation on the energy repartition of a DI Diesel engine is presented: the experimental work includes variations of coolant and oil temperatures, intake temperature and injection timing at different operating conditions. In each study, the Global Energy Balance (GEB) methodology, based on the experimental measurement of different fluid temperatures and flows, is applied to determine all the relevant energy terms, including heat flow to the coolant and oil, the exhaust gases enthalpy, and the EGR and intercooler heat rejections along with some other minor terms. This information is used to justify in detail the final effect of the parameters on the brake consumption.
2015-04-14
Technical Paper
2015-01-0363
B. vasanth
In recent years clearing the mist on side windows is one of the main criterions for all OEMs for providing comfort level to the passengers while driving. It will create poor visibility to the passengers when the mist is not cleared on side windows to the desired level. “Windows fog up excessively/don’t clear quickly” is one of the JD Power question to assess the customer satisfaction related to HVAC performance. Defrost/Demist is one of the major issues for all OEMs in recent years. In a Mobile Air Conditioning System, HVAC demister duct and outlet plays an important role for removing the mist formation on vehicle side window. Normally demister duct and outlet design is evaluated by the target airflow and velocity achieved at driver and passenger side window. Multiple flow simulation needs to be carried out for various design configurations of demister outlet until the target velocity is achieved before finalizing the design and its time consuming.
2015-04-14
Technical Paper
2015-01-1662
Manjushri Mahadev Patil, Ashok Pise, Nitin Gokhale
Recently, prediction of cylinder head temperature, using simulation techniques is one of interested tool for engineers. The main aim of this paper work is to predict the temperature field and mechanism of heat transfer prediction along cylinder head of diesel engines. Numerical analysis of conjugate heat transfer (CHT) between cylinder head and coolant was carried out. For the analysis a six cylinder, four cylinder, three cylinder, and two cylinder stationary diesel engines of different BMEP were taken. Simulation model was prepared and solved using commercial CFD software (STARCCM+ 9.O2) in two steps i.e. flow and Conjugate Heat transfer simulation. Flow simulation predicts flow distribution and its flow velocities along with its variation with respect to cylinder location and channel dimensions. Cylinder head is then used for further analysis where flow and heat transfer is solved simultaneously using CHT (conjugate heat transfer) simulation technique.
2015-04-14
Technical Paper
2015-01-1692
Walter Ferraris, Fausto Di Sciullo, Carloandrea Malvicino, Francesco Vestrelli, Fabrizio Beltramelli, Giancarlo Gotta
Automotive world is rapidly changing driven by the incoming CO2 emission regulation and the need of decreased fuel consumption for every vehicle line. The introduction of high efficiency solutions in order to get fuel consumption reduction has been already done on many vehicle systems without forgetting the cost sustainability of such solutions and with a general trend of weight reduction. For what concerns cooling systems, the increased adoption of dual level cooling loops and water cooled charge air cooling is a clear trend. The present paper proposes a compact and cost effective solution with low temperature loop cooling water cooled charge air cooler and water cooled condenser for A and B segment vehicle, with the possibility to add other exchangers to the secondary loop. All the thermal load is managed by only one radiator.
2015-04-14
Technical Paper
2015-01-0352
Kuo-Huey Chen, Jeffrey Bozeman, Mingyu Wang, Debashis Ghosh, Edward Wolfe, Sourav Chowdhury
The HVAC system imposes the largest accessory load on an electric vehicle to meet comfort heating and cooling needs. Thus the HVAC energy consumption can have a major impact on the driving range of a pure electric vehicle (EV) or an extended range electric vehicle (EREV such as Chevy Volt). Traditionally, the vehicular HVAC system is designed to cool and heat the entire cabin to provide passenger comfort. Localized cooling and heating, on the other hand, focus on keeping the passenger comfortable by creating a micro climate around the passenger. Such a system can easily adapt to the number of passengers in the car and enables zonal control. The net impact of the localized cooling and heating system is that equivalent comfort can be achieved at a reduced HVAC energy consumption rate. The present paper reports on a study for an EREV implementation of a localized cooling/heating system using thermoelectric (TE) nozzle devices to target the occupant’s chest, face, lap and foot areas.
2015-04-14
Technical Paper
2015-01-0370
Modar Horani, Osamah Rawashdeh
Traditional Heat Ventilation and Air Conditioning (HVAC) control systems are reactive by design and largely dependent on the on-board sensory data available on a Controller Area Network (CAN) bus. The increasingly common Internet connectivity offered in today’s vehicles, through infotainment and telematic systems, makes data available that may be used to improve current HVAC systems. This includes real-time outside relative humidity, ambient temperature, precipitation (i.e., rain, snow, etc.), and weather forecasts. This data, combined with position and route information of the vehicle, may be used to provide a more comfortable experience to vehicle occupants in addition to improving driver visibility through more intelligent humidity, and defrost control. While the possibility of improving HVAC control utilizing internet connectivity seems obvious, it is still currently unclear as to what extent.
2015-04-14
Technical Paper
2015-01-1652
Yukikatsu Ozaki, Keisuke Sekiya
This research developed new measurement technology for thermal analysis of the heat radiated from a hybrid vehicle transaxle case surface to the air and improved the heat radiation performance. In thermal analysis, the temperature distribution of the case surface and the amount of heat radiation from the surface to the air are measured. In order to quantify heat radiating from the surface into the air, the heat flux measurement is required. Until now, various heat flux sensors were proposed. For example, the thermopiles were used to measure the heat flux in the conventional sensors. These electrically measure the temperature difference between the surface and the back side of a thin plate with low thermal conductivity. However, conventional heat flux sensors require the installation of sensor wiring and this affects the flow field and the temperature field of measuring object. Therefore, these are unsuitable for multipoint measurement of heat flux.
2015-04-14
Technical Paper
2015-01-1713
Manfred Klaus Kirschning, Frank Reußwig
In recent years, the automotive industry has taken many efforts to satisfy the market requirements of reducing fuel consumption and the emission of pollutants. In consequence engines had to be compacted and many additional modules had to be integrated into the confines of tightly packed engine compartments. The narrow confines also limited the options for piping options, for instance with preformed rubber tubes or oil flow and return pipes. Many of these components are designed for a maximum permanent temperature of 140°C to 180°C only. Other components, for example oil pipes, cannot be applied in settings with temperatures higher than 140°C because of the cracking of the hydrocarbon molecules.
2015-04-14
Technical Paper
2015-01-1702
Alex Wang, Jung Hsien Yen
This paper presents a novel technology to achieve world lowest power (4W) FOG lamp by single LED design which is much enhanced than the existing 2-3 LEDs solutions. This design saves 92.7% energy than conventional Halogen lamp(55W) and saves 38.4% than existing LED FOG lamp(6.5W). The optical design adopts the optimized multifaceted reflector, with precise and unique optimization design scheme, we are able to generate a very sharp cut-off line with a 3.2W LED to enable stronger light penetration in low vision weather condition. The efficiency of multifaceted reflector optics in this study is 50.9% which is 27% higher than the existing reflector design. Design details, anti-block skills and the manufacturing tolerance control are analyzed in this paper. The total light output of the LED fog lamp is 210lm, the L6-line minimal is 4200cd above the ECE R19 requirement of 2700cd.
2015-04-14
Technical Paper
2015-01-0333
Ravi Badathala, Kaushal Kumar Jha
Due to Increase in demand of comfort in vehicle cabin, thermal management of cabin became very important parameter in Automotive HVAC system. Estimated component performance with test bench conditions, are always not same when components are working along with other HVAC components in actual working conditions. Developing accurate simulation models to predict the HVAC performance at different test cycles using component level performance curves, gives a reliable insight to the HVAC behavior during a performance test. This will also reduce the physical effort & test cost. To ensure the components are well versed with the vehicle working environment a, virtual model of transient condition with control logic has been developed using commercial 1D software. During the transient simulation of HVAC System performance for a cool down test with compressor and evaporator Controls, balancing of individual components with other system components is ensured.
2015-04-14
Technical Paper
2015-01-0356
Aniket Patil, Manoj Radle, Biswadip Shome, Sankar Ramachandran
Passenger comfort and safety are major drivers in a typical automotive design and optimization cycle. To address thermal comfort requirements, thermal management of the passenger cabin in a car which involves accurately predicting the temperature of the cabin interior space and the various aggregates that are present in a cabin, has become an area of active research. Traditionally, these has been done using experiments or detailed three-dimensional Computational Fluid Dynamics (CFD) analysis, which are both expensive and time-consuming. To alleviate this, recent approaches have been to use one-dimensional system-level simulation techniques with a goal to shorten the design cycle time and reduce costs. This paper describes the use of Modelica Language to develop a one-dimensional mathematical model using Dymola for automotive cabin thermal assessment when the car is subjected to solar heat loading.
2015-04-14
Technical Paper
2015-01-0720
Dinesh Pahuja, Vijay kumar, Arpit Kapila
Door trim insert plays a very important role for making vehicle aesthetic appealing and pleasing through addition of skin over the Door trim insert substrate. In automotive industry, for side door trim insert decoration and skin pasting, large number of bonding techniques are available. This paper will focus mainly on analyzing the effect of skin type and its construction on automotive side door trim insert having thermo compression molding as a pasting technique. Properties of skin like elongation and bending resistance etc., affect the appearance of door trim insert after pasting of skin. And the selection of skin type and specifying its properties for door trim insert is a challenge for an automotive interior designer. In automotive applications, different materials are used for Door trim insert skin e.g. woven fabric, knit fabric, PVC and leather.
2015-04-14
Technical Paper
2015-01-1611
Wei Liu
When the hydraulic retarder is working in the heavy-duty vehicle, almost all the braking power is transformed into the thermal energy of the transmission oil. The spare heat removal capacity of engine’s cooling system could be taken full advantage for cooling the retarder. However, the relative long distance of the engine and the retarder increases the risky leakage of the cooling circuit. Furthermore, the development trend of heavy load and high speed vehicle directs the significant increase in the thermal load of the hydraulic retarder, which even higher than the engine power. Conventional engine cooling system could not meet the demand of the hydraulic retarder heat rejection within the same installation space. In this research, independent two-phase evaporator was adopted to strengthen the coolant heat absorption capacity from the transmission fluid at the oil outlet of the retarder by means of the vacuum flow boiling heat transfer.
2015-04-14
Technical Paper
2015-01-1606
Saroj Pradhan, Arvind Thiruvengadam, Pragalath Thiruvengadam, Marc C. Besch, Daniel Carder
Heavy-duty diesel (HDD) engines are the primary propulsion source for most heavy-duty vehicle freight movement and have been equipped with an array of aftertreatment devices to comply with more stringent emissions regulations. In light of concerns about the transportation sector's influence on climate change, legislators are introducing requirements calling for significant reductions in fuel consumption and thereby, greenhouse gas (GHG) emission over the coming decades. Advanced engine concepts and technologies will be needed to boost engine efficiencies. However, increasing the engine’s efficiency is inevitably linked to a reduction in thermal energy of the exhaust gas. Thus contributing to lower exhaust temperature of after-treatment activity, necessary for maintaining the aftertreatment system within a favorable temperature range.
2015-04-14
Technical Paper
2015-01-1660
Jose Ramon Serrano, Francisco Arnau, Jaime Martin, Manuel Hernandez, Benoit Lombard
This paper presents experiments on the effect of thermal insulation of engine internal walls on the performance and emissions of a heavy-duty diesel engine. Some parts of the engine, like pistons, cylinder head and exhaust manifold were insulated in order to reduce heat loses through the walls. Each component has been analysed first independently and then in combination with others. The results obtained in a test bench have been compared to the original engine configuration. This analysis focuses on parameters such as NOx emissions, smoke and break specific fuel consumption. In order to take advantage of the engine insulation, a swept of the injection setting was also performed, which provided the best combination of start of injection (SOI) and pump injector needle opening pressure (NOP).
2015-04-14
Technical Paper
2015-01-0346
Lei dongxu
Due to the latent heat of vaporization, the efficiency of boiling heat transfer is several times and even dozens of times higher than that of the convection heat transfer. With the improvement of power density of the engine, there are more requirements for engine cooling system design. It has been confirmed that the subcooled boiling did exist in the engine cooling. If boiling heat transfer can be reasonablely used, we can achieve the objective of enhancing heat transfer without changing the existing structure. In this paper, in order to quantitatively research the subcooled boiling in the engine, we simulated the subcooled boiling in the analog channel with the Euler multiphase model, found the importance of the turbulent dispersion. In additon, we explored the applicability of existing models to subcooled boiling, and compared the results with the experiment.
2015-04-14
Technical Paper
2015-01-0365
Gursaran D. Mathur
In a recent investigation (Mathur, 2014), the author had investigated the amount of energy stored in vehicle's Cockpit Module (CPM) at high ambient and at high solar heat loads for a MY2012 production vehicle. Detailed analysis was presented to show the influence of energy stored in various components (e.g., instrument panel, HVAC system, heat exchanger, wire harness, etc.) contained within the CPM unit. Experiments were conducted to show the amount of energy stored at high ambient and solar conditions. This is a follow up study to the above investigation. In this investigation, same vehicle is used to determine the amount of energy stored at cold temperatures, say at -20°C temperature that is used for a majority of heating, windshield and window de-fogging and de-icing tests.
2015-04-14
Technical Paper
2015-01-0351
Jason Aaron Lustbader, Cory Kreutzer
Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States. Idling of the truck during a rest period represents a zero freight efficiency condition and is partially done to supply accessory power for climate conditioning of the cab. The U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory’s (NREL) CoolCab project aims to reduce HVAC loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings from new technologies provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them.
2015-04-14
Technical Paper
2015-01-0369
Rupesh Sonu Kakade
Apart from thermal comfort of occupants, their safety by ensuring adequate visibility is the primary objective of automotive climate control systems. Integrated dew point and glass temperature is widely used senor among several technologies to detect risk of fog formation on the windshield. The erroneous information from sensor such as the measurement lag can cause imperfect visibility due to delayed response of climate control system. A differential equation model of cabin air humidity is proposed to calculate in real-time the ambient humidity of passenger compartment. The specific humidity from the model is used to determine relative humidity for a known window surface temperature. The uniform spatial distribution of cabin air humidity is used to advantage. However non-uniform distribution of window surface temperature and the uncertainty of parameters of differential equation model are evaluated to determine risk of fogging to an acceptable accuracy.
Viewing 1 to 30 of 7571