Search Results

The 14 papers in this technical paper collection discuss thermal systems modeling and simulation. Topics covered include fuel efficiency and thermal performance, exhaust system manifold development, engine cooling systems with a double circuit, CFD analysis, and more. The 14 papers in this technical paper collection discuss thermal systems modeling and simulation. Topics covered include fuel efficiency and thermal performance, exhaust system manifold development, engine cooling systems with a double circuit, CFD analysis, and more.

Proper thermal management can significantly contribute to overall system energy efficiency. The papers in this collection highlight the latest developments in thermal management energy efficiency.

Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance is critical to customer satisfaction. The primary objective is to deliver occupant safety and thermal comfort at minimum energy consumption, yet the system has strong design interaction with other vehicle systems. Noise, Air Quality, and Energy ace are just a few of the recent advances.

The papers in this collleciton focus on state of the art simulation technologies for modeling thermal systems and their application in the development and optimization of vehicle thermal management and fuel economy. The papers range from empirical, 1D modeling methods to three dimensional CFD models as well as coupled methods.

Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance is critical to customer satisfaction. The primary objective is to deliver occupant safety and thermal comfort at minimum energy consumption, yet the system has strong design interaction with other vehicle systems. Noise, Air Quality, and Energy ace are just a few of the recent advances.

The papers in this collleciton focus on state of the art simulation technologies for modeling thermal systems and their application in the development and optimization of vehicle thermal management and fuel economy. The papers range from empirical, 1D modeling methods to three dimensional CFD models as well as coupled methods

The papers included in this collection cover modeling (zero-D, 1D, 2D, 3D CFD) and experimental papers on: combustion chamber, systems (lubrication, cooling, fuel, EGR); components (oil pumps, coolant pump, fuel injectors, compressors, turbines, turbochargers, torque converters, gear box, fans, bearings, valves, ports, manifolds, turbine housing); heat exchangers (radiators, oil coolers); aftertreatment (SCR, DOC, DOF, exhaust gas cooling); battery cooling (HEV, EV, motor/generator) and controls (passive and active).

Advanced vehicular thermal management system can improve engine performance, minimize fuel consumption, and reduce emissions by harmoniously operating computer-controlled servomotor components. In this paper, a neural network-based optimal control strategy is proposed to regulate the engine temperature through the advanced cooling system. Presenter Asma Al Tamimi, Hashemite University

Today CFD is an important tool for engineers in the automotive industry who model and simulate fluid flow. For the complex field of Underhood Thermal Management, CFD has become a very important tool to engineer the cooling airflow process in the engine bay of vehicles. Presenter Peter Gullberg, Chalmers University of Technology

EGR coolers are used in combustion engines to reduce NOx emissions. However, heat transfer in these coolers also results in thermophoresis-temperature-gradient driven motion of suspended particles towards cooler regions-which leads to significant soot deposition. Presenter Meisam Mehravaran

Zero-dimensional, one-dimensional, and quasi-dimensional models for simulation of SI and CI engines with respect to: engine breathing and boosting; SI combustion and emissions; CI combustion and emissions; fundamentals of engine thermodynamics; thermal management; mechanical and lubrication systems; system level models for controls; system level models for vehicle fuel economy and emissions predictions. Presenter Fabio Bozza, Universita di Napoli

Combustion engines are typically only 20-30% efficient at part-load operating conditions, resulting in poor fuel economy on average. To address this, LiquidPiston has developed an improved thermodynamics cycle, called the High-Efficiency Hybrid Cycle (HEHC), which optimizes each process (stroke) of the engine operation, with the aim of maximizing fuel efficiency. The cycle consists of: 1) a high compression ratio; 2) constant-volume combustion, and 3) over-expansion. At a modest compression ratio of 18:1, this cycle offers an ideal thermodynamic efficiency of 74%. To embody the HEHC cycle, LiquidPiston has developed two very different rotary engine architectures ? called the ?M? and ?X? engines. These rotary engine architectures offer flexibility in executing the thermodynamics cycle, and also result in a very compact package. In this talk, I will present recent results in the development of the LiquidPiston engines. The company is currently testing 20 and 40 HP versions of the ?M?

Historically, the opposed-piston, two-stroke (OP2S) diesel engine set combined records for fuel efficiency and power density that have yet to be met by any other engine type. However, with modern emissions standards, wide-spread development of this engine for on-highway use stopped. At Achates Power, state-of-the-art analytical tools and engineering methods have produced an OP2S engine that, when compared to a leading medium-duty engine, has demonstrated a 21% fuel efficiency gain and engine-out emissions levels meeting U.S. EPA10 with conventional after-treatment. Among the presentation topics covered are thermodynamic efficiency, demonstrated engine results, cost and weight advantages, and overcoming two-stroke engine challenges. Presenter David Johnson, Achates Power Inc.

Ford's thermal management with batteries. Presenter Robert Taenaka, Ford Motor Co.

PROVISION is made, in the piston and rings described by the author, for an adequate flow of heat from all parts of the piston-head to the cylinder-wall by means of adequate cross-section of aluminum alloy in the head and a tongue-and-groove type of piston-ring structure which provides a greater amount of surface than is usual for heat transfer. A labyrinth oil-seal is provided which aids heat transference and prevents leakage past the piston-rings, and the heat transfer is said to be such that the heat does not destroy the oil seal between the piston and the ring. Charts are included that show the effects in reduced temperatures, oil consumption and gas leakage with the construction described. Attention is given also to a skirt construction most suitable to use with the piston-head and rings described.

FROM 25 to 35 per cent of the heat energy of the fuel inducted into the cylinders of an internal-combustion engine must be eliminated by the cooling system. As this waste requires the expenditure of energy, the devising of an efficient cooling system is imperative. The author, who is a leading American authority on engine problems, discusses the theory of liquid-cooling, gives heat-transfer and temperature-balance equations that must be satisfied and points out the three interrelated variable factors that must be incorporated in their most economical relation. The cooling system must be studied as a whole, rather than from the standpoint of any particular unit. Some commonly held beliefs regarding fans, fuel-pumps and oil-temperature control are controverted. Five elements necessary for an efficient cooling system are enumerated.

SATISFACTORY performance of a lubricant depends upon characteristics of the lubricant, operating conditions and design of the device in which the lubricant is used. Applied lubrication requires a study of the relation among these factors in their effect upon performance. The authors treat journal bearings, ball and roller bearings and gears. Equations are given for journal bearings operating under various conditions of design, lubrication, friction and heat dissipation. The authors conclude that neither ZN/P nor PV alone is adequate as a measure of the power dissipated by a bearing, a composite relation involving both terms being required over a large part of the operating range. They show that each bearing has a minimum value of ZN/P below which it may get into the unstable region of thin-film lubrication and fail.

The development of intake-manifolds in the past has been confined mainly to modifications of constructional details. Believing that the increased use of automotive equipment will lead to a demand for fuel that will result in the higher cost and lower quality of the fuel, and being convinced that the sole requirement of satisfactory operation with kerosene and mixtures of the heavier oils with alcohol and benzol is the proper preparation of the fuel in the manifold, the authors have investigated the various methods of heat application in the endeavor to produce the minimum temperature necessary for a dry mixture. Finding that this minimum temperature varied with the method of application of the heat, an analysis was made of the available methods on a functional rather than a structural basis.

In the first part of the paper, a general quantitative comparison of air, water and oil-cooled cylinders is given as it relates to the subject of heat-transfer and temperature drop. Unfortunately, the discussion does not include experimental data, but the assumptions are stated clearly and a large range of values is covered in Table 2 so that any desired values can be chosen. A thorough and comprehensive discussion of the steam or the radio-condenser type of cooling is given under the headings of Steam Cooling Systems, Characteristics of Steam Cooling Systems, Cooling Capacity of Radiators Used To Condense Steam and Present State of Development. In the second part, an attempt is made to give a thorough but brief discussion of the performance or of the operating characteristics of radiators from the point of view of the car, truck or tractor designer. The cooling of aircraft engines is not considered.

Annual Meeting Paper - The heat-dissipating properties of three types of radiator core have been investigated at the Mason Laboratory, Yale University. These include the fin-and-tube, the ribbon and the air-tube groups, so classified according to the flow of the water and the air. The ratio of the cooling surface to the volume is shown to be nearly the same in the fin-and-tube and the air-tube cores, while that of the ribbon core is somewhat greater. A formula is derived for computing the heat-transfer coefficient, which is defined as the number of heat units per hour that will pass from one square foot of surface per degree of temperature-difference between the air and the water and is the key to radiator performance, as by it almost any desired information can be obtained. When the heat-transfer coefficients have been found for a sufficiently wide range of water and air-flows the cooling capacity of a radiator can be computed for any desired condition.