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Viewing 91 to 120 of 10087
2015-04-14
Technical Paper
2015-01-0355
Matthew A. Jeffers, Larry Chaney, John P. Rugh
Abstract Passenger compartment climate control is one of the largest auxiliary loads on a vehicle. Like conventional vehicles, electric vehicles (EVs) require climate control to maintain occupant comfort and safety, but cabin heating and air conditioning have a negative impact on driving range for all-electric vehicles. Range reduction caused by climate control and other factors is a barrier to widespread adoption of EVs. Reducing the thermal loads on the climate control system will extend driving range, thereby reducing consumer range anxiety and increasing the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have investigated strategies for vehicle climate control load reduction, with special attention toward EVs. Outdoor vehicle thermal testing was conducted on two 2012 Ford Focus Electric vehicles to evaluate thermal management strategies for warm weather, including solar load reduction and cabin pre-ventilation.
2015-04-14
Technical Paper
2015-01-0356
Aniket Patil, Manoj Radle, Biswadip Shome, Sankar Ramachandran
Abstract Passenger comfort and safety are major drivers in a typical automotive design and optimization cycle. Addressing thermal comfort requirements and the thermal management of the passenger cabin within a car, which involves accurate prediction of 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 have 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 Modelica language for automotive cabin thermal assessment when the car is subjected to solar heat loading.
2015-04-14
Technical Paper
2015-01-0353
Kaushal Kumar Jha, Ravi Badathala
Abstract The prime focus of automotive industries in recent times is to improve the energy efficiency of automotive subsystem and system as whole. Harvesting the waste energy and averaging the peak thermal loads using thermal energy storage (TES) materials and devices can help to improve the energy efficiency of automotive system and sub-system. The phase change materials (PCM) well suit the requirement of energy storage/release according to demand requirement. One such example of TES using PCM is extended automotive cabin comfort during vehicle idling and city traffics including start/stop of the engine at traffic stops. PCM as TES poses high density and capacity in thermal energy storage and release. It is due to latent heat absorption and release during phase change. Generally the latent heat of a material compare to it sensible heat is much higher, almost an order of 2.
2015-04-14
Technical Paper
2015-01-0354
Ji Wan Kim, Tae Hee Lee
Abstract This study has been conducted to analyze microbial diversity and its community by using a method of NGS(Next generation sequencing) technique that is not rely on cultivation for microbial community in an core evaporator causing odor of car air conditioner. The NGS without any cultivation method of cultivation, has been developed recently and widely. This method is able to research a microorganism that has not been cultivated. Differently with others, it can get a result that is closer to fact, also can acquire more base sequence with larger volume in relatively shorter time. According to bacteria population analysis of 23 samples, It can be known limited number of bacteria can inhabit in Evaporator core, due to small exposure between bacteria and evaporate, as well as its environmental characteristics. With the population analysis, only certain group of it is forming biofilm in proportion.
2015-04-14
Technical Paper
2015-01-0360
Maryline Leriche, Wolfgang Roessner, Heinrich Reister, Bernhard Weigand
Abstract An accurate model to predict the formation of fogging and defogging which occurs for low windshield temperatures is helpful for designing the air-conditioning system in a car. Using a multiphase flow approach and additional user-defined functions within the commercial CFD-software STAR-CCM+, a model which is able to calculate the amount of water droplets on the windshield from condensation and which causes the fogging is set up. Different parameters like relative humidity, air temperature, mass flow rate and droplet distributions are considered. Because of the condition of the windshield's surface, the condensation occurs as tiny droplets with different sizes. The distribution of these very small droplets must be obtained to estimate numerically the heat transfer coefficient during the condensation process to predict the defogging time.
2015-04-14
Technical Paper
2015-01-0358
Praveen Balaj Balakrishnan, Xiaoyong Yu, Ka Chung Chan, Chi Yan Tso, Christopher Chao
Abstract An adsorption air conditioning system is proposed to provide cabin comfort cooling for automotives. This report focuses on the development of a compact adsorption cooling system for automobile applications and its experimental performance. This system uses AQSOA - Z01, an adsorbent material that adsorbs and regenerates water efficiently at low temperature ranges. A water circulation system was built to simulate the process of obtaining heat from exhaust gas heat and providing low-grade thermal energy for the adsorption cooling system. As this system does not need to be powered by the engine as it is in the conventional system, fuel efficiency of the engine can be improved by 10%. This also results in reduction of pollutants due to combustion. The prototype is produced a maximum1310 Watts of cooling power. The system also achieved 650 W/kg SPC (Specific Cooling Power) and a COP (Coefficient of Performance) value of 0.45.
2015-04-14
Technical Paper
2015-01-0363
Vasanth Balashunmuganathan, Ramakrishna Nukala, Sathishkumar Sampath Kumar, Murali Govindarajalu
In recent years clearing the mist on side windows is one of the main criterions for all OEMs for providing comfort level to the person while driving. Visibility through the side windows will be poor when the mist is not cleared 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. 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. The methodology for optimizing the demister outlet located at side door trim has been discussed. Detailed studies are carried out for creating a parametric modeling and optimization of demister outlet design for meeting the target velocity.
2015-04-14
Technical Paper
2015-01-0364
Yinhua Zheng
This paper presents the way to optimize vehicle AC system TXV to meet the various AC system requirements. It discusses vehicle AC system TXV sizing and selection process. In today's automotive industry, sizing and selecting the TXV is more complicated than before as various new components are introduced such as external control compressor, internal control compressors and internal heat exchanger etc. These components complicated the system interaction among the components. Thus it requires mapping TXV characteristic to meet the system demand. Sizing TXV capacity, it must start with the vehicle heat load requirement. The type of TXV (i.e. cross charge or parallel charge head) is determined by the system configuration such as compressor, evaporator, and condenser type and with or without internal heat exchanger, etc. To optimize TXV in the system involves in evaluating TXV characteristic and cooling capacity in the various AC operating conditions.
2015-04-14
Technical Paper
2015-01-0361
Yang Zou, Pega Hrnjak
Abstract Although refrigerant maldistribution among parallel microchannel tubes is mainly caused by phase separation of vapor and liquid in the header, it is also affected by pressure drop in the header. This study experimentally investigates the pressure drop of single-phase and two-phase R134a flow in the vertical header of a multi-pass microchannel heat exchanger. R134a is circulated into the transparent header through multi-parallel microchannel tubes in the bottom pass and exits through multi-parallel microchannel tubes in the top pass representing the flow in the heat pump mode of a reversible system. The pressure drop in the vertical header causes the top tube has lower mass flow rate than the lower tubes for both single-phase and two-phase flow. The overall pressure drop in the header includes four components: acceleration, gravitation, friction, and minor pressure drop due to microchannel tube protrusion.
2015-04-14
Technical Paper
2015-01-0362
Neal Lawrence, Stefan Elbel
Abstract Much attention has been given in recent years to the use of two-phase ejectors and particularly to the performance of the standard ejector cycle with a liquid-vapor separator. However, this cycle may not be the best choice for automotive applications due to the large size required by an efficient separator as well as the cycle's performance at conditions of lower ejector potential. A limited amount of recent research has focused on alternate two-phase ejector cycles that may be better suited for automotive applications. One of these cycles, using the ejector to allow for evaporation at two different temperatures and eliminating the need for a separator, will be the subject of investigation in this paper. Previous investigations of this cycle have been mainly theoretical or experimental; this paper aims to provide a numerical analysis of the effect of evaporator design on the performance of the ejector cycles.
2015-04-14
Technical Paper
2015-01-0367
Zhiqiang Hu, Gangfeng Tan, Zhilei Li, Haobo Xu, Wenhui Huang, Yifan Ye
Abstract The cabin air temperature increases quickly and can reach 80°C when the vehicle parks in the summer sunlight which has the bad influence on the occupants entering comfort. Some luxury vehicles, like Audi A8[1], reduce the internal temperature through operating 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 operating time because of energy consumption. This research adopts the solar wing 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.
2015-04-14
Technical Paper
2015-01-0368
Janampally Sandeep Kumar Reddy, Shailendra Deopa, Abhay Sharma, Piyush Aggarwal
Abstract Bumper opening area projected on condenser to total condenser core area is referred to as condenser opening area. The condenser opening area plays a vital role in A/C Performance of vehicle particularly during idling and initial cooling of vehicle. This paper presents detail study on effects of condenser opening area on A/C performance. Based on theory, the effect of condenser opening area is studied and it is validated by experimental results. Depending on these results an optimum value of condenser opening area required for best A/C performance is concluded.
2015-04-14
Technical Paper
2015-01-0365
Gursaran D. Mathur
Abstract Experimental studies have been conducted to determine the energy stored in vehicle's Cockpit Module (CPM) at cold soaking conditions for a MY2012 production vehicle. Detailed analysis has been done in this paper 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 conducted show that the instrument panel stores the maximum amount of energy at a given temperature.
2015-04-14
Technical Paper
2015-01-0366
Cristian Rostiti, Stephanie Stockar, Marcello Canova
Abstract In a conventional passenger vehicle, the AC system is the largest ancillary load. This paper proposes a novel control strategy to reduce the energy consumption of the air conditioning system of a conventional passenger car. The problem of reducing the parasitic load of the AC system is first approached as a multi-objective optimization problem. Starting from a validated control-oriented model of an automotive AC system, an optimization problem is formalized to achieve the best possible fuel economy over a regulatory driving cycle, while guaranteeing the passenger comfort in terms of cabin temperature and reduce the wear of the components. To complete the formulation of the problem, a set of constraints on the pressure in the heat exchanger are defined to guarantee the safe operation of the system. The Dynamic Programming (DP), a numerical optimization technique, is then used to obtain the optimal solution in form of a control sequence over a prescribed driving cycle.
2015-04-14
Technical Paper
2015-01-0399
Alexander Jaust, Bastian Morcinkowski, Stefan Pischinger, Jens Ewald
Abstract In this work, a transport and mixing model that calculates mixing in thermodynamic phase space was derived and validated. The mixing in thermodynamic multizone space is consistent to the one in the spatially resolved physical space. The model is developed using a turbulent channel flow as simplified domain. This physical domain of a direct numerical simulation (DNS) is divided into zones based on the quantitative value of transported scalars. Fluxes between the zones are introduced to describe mixing from the transport equation of the probability density function based on the mixing process in physical space. The mixing process of further scalars can then be carried out with these fluxes instead of solving additional transport equations. The relationship between the exchange flux in phase space and the concept of scalar dissipation are shown and validated by comparison to DNS results.
2015-04-14
Technical Paper
2015-01-0442
Sudhi Uppuluri, Ajay Naiknaware
This paper discusses the sensitivity of key parameters that are used as an input into engine cooling system simulation model that affect the coolant temperature and required airflow calculations. In simulation, these parameters are obtained either from calculations of other programs such as a combustion program or from measured engine test data and are typically assumed to be constant. Tests and measurements from vehicle tests indicate that these parameters always vary affecting the final predicted coolant temperature. The sensitivity on few selected parameters such as the ambient pressure, temperature, humidity, coolant properties among others were studied. Results discussed in this paper quantify the effect of each of these parameters on required airflow and advise which parameters must be tightly controlled to improve the robustness of the simulation model and the accuracy of predictions.
2015-04-14
Technical Paper
2015-01-0613
Donghong Ning, James Coyte, Hai Huang, Haiping Du, Weihua Li
Abstract This paper presents a study on experimental vibration simulation using a multiple-DOF motion platform for heavy duty vehicle seat suspension test. The platform is designed to have 6-DOF with the advantages of high force-to-weight ratio, high dexterity and high position accuracy. It can simulate vehicle vibrations in the x, y and z translational axis and in the roll pitch and yaw axis rotation. To use this platform to emulate the real vibration measured from vehicle seat base under real operation for vehicle seat suspension test in lab, an Inertial Measurement Unit (IMU) is applied to collect the acceleration data from a real vehicle. An estimation algorithm is developed to estimate the displacement from the measured acceleration. The estimated displacement is then used to calculate the length of each leg of the platform so that the platform can generate the motion similar to the measured one.
2015-04-14
Technical Paper
2015-01-1651
Francisco Payri, Jaime Martin, Antonio Garcia, Ricardo Carreño
Abstract In recent years, the spread use of after-treatment systems together with the growing awareness about the climate change is leading to an increase in the importance of the efficiency over other criteria during the design of internal combustion engines. In this sense, it has been demonstrated that performing an energy balance is a suitable methodology to assess the potential of different injection or air management strategies, to reduce consumption as well as determining the more relevant energy terms that could be improved. In this work, an experimental energy balance with the corresponding comprehensive analysis is presented. The main objective is the identification of how the energy is split, considering internal and external balances. For this purpose, some parametric studies varying the coolant temperature, the intake air temperature and the start of the injection timing have been performed. The results quantify the effect of each parametrical study on engine efficiency.
2015-04-14
Technical Paper
2015-01-1623
Ivan Arsie, Rocco Di Leo, Stefano Falco, Cesare Pianese, Matteo De Cesare
Abstract International regulations continuously restrict the standards for the exhaust emissions from automotive engines. In order to comply with these requirements, innovative control and diagnosis systems are needed. In this scenario the application of methodologies based on the in-cylinder pressure measurement finds widespread applications. Indeed, almost all engine thermodynamic variables useful for either control or diagnosis can be derived from the in-cylinder pressure. Apart for improving the control accuracy, the availability of the in-cylinder pressure signal might also allow reducing the number of existing sensors on-board, thus lowering the equipment costs and the engine wiring complexity. The paper focuses on the detection of the engine thermal state, which is fundamental to achieve suitable control of engine combustion and after-treatment devices.
2015-04-14
Technical Paper
2015-01-1609
Roberto Monforte, Francesco Lovuolo, Matteo Rostagno, Riccardo Seccardini, Teron Matton
Abstract Following the development of new technologies in Vehicle Thermal Management aiming to both enhancing the MAC System efficiency and reducing the thermal load to be managed, a prediction tool based on the AMEsim platform was developed at Advanced PD EMEA. This tool is dedicated to predict the effect of the implementation of sensors monitoring both the relative humidity and the carbon dioxide (CO2) concentration (taking into account passengers' generated moisture and CO2). This model implemented with the usual comfort inputs (CO2 and RH acceptable ranges) considers the system variables influencing the comfort and predicts the increase of both RH and CO2 concentration in the cabin compartment in any driving cycle depending on the number of occupants.
2015-04-14
Technical Paper
2015-01-1610
Xiaomeng Shen, Gangfeng Tan, Quan Zhou, Zhongjie Yang, Min Hua
Abstract The Organic Rankine Cycle System is an effective approach for recovering the engine exhaust thermal energy. The physical characteristic of the Rankine fluid is the key factor for the capacity and the stability of the expander power output. In the research, the influences of the evaporator organic medium state and flow rate on the expander power output are fully analyzed for the sufficient utilization of the waste thermal energy. Firstly, the exhaust characteristics of the diesel engine were processed by the data of the bench test. Then, the integral mathematical model of the Organic Rankine Cycle was built. Based on the comparison for the 2-zone and 3-zone evaporator, the influence for expander output are analyzed especially emphasis on the factors of engine working condition, the flow rate, temperature and state of Rankine fluid.
2015-04-14
Technical Paper
2015-01-1605
Hee Sang Park
Abstract Electric powered vehicles rely on electric heater to heat the cabin of the vehicle. These heaters consume electric energy from the battery and cause depletion of the vehicle's range by 20∼40%. In order to extend the range of electric vehicles, we need to increase the efficiency of HVAC. EV has waste heat but the heat power is much lesser than internal combustion engine and heat source is separated physically. In order to utilize waste heat to achieve better efficiency, heat collection, heat insulation, pre-heating are necessary. Based on the new concept system, we examined the effects of fuel efficiency
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 may result in a reduction in thermal energy of the exhaust gas, thus contributing to lower exhaust temperature, potentially affecting aftertreatment activity, and consequently rate of regulated pollutants. This study investigates the possible utilization of waste heat recovered from a HDD engine as a means to offset fuel penalty incurred during thermal management of SCR system.
2015-04-14
Technical Paper
2015-01-1607
Chuen-Sen Lin, Vamshi Avadhanula, Vamsi Mokkapati, Daisy Huang, Brent Sheets
This paper presents test results of a 50 kW Organic Rankine Cycle (ORC) system and proposed guidelines for how to effectively apply this system to the rural Alaska power industry. In rural Alaska, approximately 180 villages rely on off-grid diesel generators for power. Most of the generators have capacities of about 1 MW or less. In general, the average operation efficiencies are noticeably less than 40%, with the rest of the fuel energy becoming heat. If the heat is not applied for useful application, it is called waste heat. Most of the wasted heat is contained in engine exhaust and jacket fluid and eventually dissipates into the environment. For rural Alaska, waste heat for heating is most effective; in many cases, waste heat for power may be needed due to a variety of reasons. Many rural Alaskan villages are reluctant to apply exhaust heat recovery due to concerns about corrosion and soot accumulation in the exhaust system and their effect on emissions.
2015-04-14
Technical Paper
2015-01-1608
Davide Di Battista, Marco Mauriello, Roberto Cipollone
Abstract A smart way to reduce CO2 emission in transportation sector is to recover energy usually wasted and re-use it for engine and vehicle needs. ORC plant on exhaust gas of ICE is really interesting, but it has a significant impact on the exhaust line and vehicle's weight. The backpressure realized in the exhaust and the weight gain, in fact, produce a specific fuel consumption increase as well as an increase in the propulsion power: both terms could vanish the energy recovered. The paper discusses the effects of the pressure losses produced by an ORC plant mounted on the exhaust line of an IVECO F1C test bench engine. The interactions produced on the turbocharged engine have been experimentally investigated: the presence of an IGV turbocharger makes the effect of the backpressure not straightforward to be predicted and needed a full experimental testing of the group in order to understand its reaction and the net effect in terms of specific fuel consumption.
2015-04-14
Technical Paper
2015-01-0147
Matthew J. Pitts, Elvir Hasedžić, Lee Skrypchuk, Alex Attridge, Mark Williams
Abstract The advent of 3D displays offers Human-Machine Interface (HMI) designers and engineers new opportunities to shape the user's experience of information within the vehicle. However, the application of 3D displays to the in-vehicle environment introduces a number of new parameters that must be carefully considered in order to optimise the user experience. In addition, there is potential for 3D displays to increase driver inattention, either through diverting the driver's attention away from the road or by increasing the time taken to assimilate information. Manufacturers must therefore take great care in establishing the ‘do’s and ‘don’t's of 3D interface design for the automotive context, providing a sound basis upon which HMI designers can innovate. This paper describes the approach and findings of a three-part investigation into the use of 3D displays in the instrument cluster of a road car, the overall aim of which was to define the boundaries of the 3D HMI design space.
2015-04-14
Technical Paper
2015-01-0169
Kazuyuki Nakata, Maya Seki, Ryoichi Nishikawa, Soju Matsumoto, Shinichiro Murakami, Yukio Yoshino
Abstract Instrument clusters that display all information on a TFT-LCD screen, also known as reconfigurable instrument clusters, have become the new trend in automotive interiors. DENSO mass-produced the world's first reconfigurable instrument cluster in 2008. To satisfy customer requirements, large quantities of resources were required. Coupled with an iterative process due to requirement changes, development costs became very high. Reducing development costs was vital in order to expand the reconfigurable instrument cluster product line. A new artist-centric HMI (human machine interface) software development workflow is proposed to reduce the development effort by introducing a data converter and real-time 3D rendering engine in our earlier paper. Our goal is to realize an environment with little programming during development by utilizing a tool chain to automate the majority of the programmer's tasks.
2015-04-14
Technical Paper
2015-01-0476
Hyunkwon Jo, Youngseung Kim, Hyunchul Lee, Hyunmin Park, Suckin Song
Abstract Carmakers have tried to lower the vehicle weight for raising fuel efficiency. This trend involves a trade-off with the vehicle stiffness. In automobile interior parts, the thickness has needed to be decreased for the weight reduction but this makes the stiffness worse. A new approach for improving the stiffness due to the weight reduction is required and various optimization methods at early development stage have been introduced currently. However, it is difficult to apply optimization for the interior parts since many interior parts' structures generally depend on the design. But as studying the structure in detail, we discovered some factors that affect the performance without depending on design. The door trim is selected for optimization item because it has many characteristics of automobile interior parts. In our case study, the factors that improve the performance of door trim without changing design are considered as fastener position and flange rib layout.
2015-04-14
Technical Paper
2015-01-0505
Miguel Angel Reyes Belmonte, Colin D. Copeland, Drummond Hislop, George Hopkins, Adrian Schmieder, Scott Bredda, Sam Akehurst
Abstract Pressure and temperature levels within a modern internal combustion engine cylinder have been pushing to the limits of traditional materials and design. These operative conditions are due to the stringent emission and fuel economy standards that are forcing automotive engineers to develop engines with much higher power densities. Thus, downsized, turbocharged engines are an important technology to meet the future demands on transport efficiency. It is well known that within downsized turbocharged gasoline engines, thermal management becomes a vital issue for durability and combustion stability. In order to contribute to the understanding of engine thermal management, a conjugate heat transfer analysis of a downsized gasoline piston engine has been performed. The intent was to study the design possibilities afforded by the use of the Selective Laser Melting (SLM) additive manufacturing process.
2015-04-14
Technical Paper
2015-01-0331
Sina Shojaei, Simon Robinson, Chris Chatham, Andrew McGordon, James Marco
Abstract Among the auxiliary systems on electric and hybrid electric vehicles the electric air conditioning (eAC) system causes the largest load on the high voltage battery and can significantly impact the energy efficiency and performance of the vehicle. New methods are being investigated for effective management of air conditioning loads through their integration into vehicle level energy management strategies. For this purpose, a fully integrated vehicle model is developed for a commercially available hybrid vehicle and used to develop energy management algorithms. In this paper, details of the eAC model of this vehicle are discussed, including steady state component validation against rig data. Also results of simulating the cabin pull-down are included.
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