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An integrated engineering approach using computer modeling, laboratory and vehicle testing enabled the Ford GT engineering team to achieve supercar thermal management performance within the aggressive program timing. Theoretical and empirical test data was used during the design and development of the engine cooling system. The information was used to verify design assumptions and validate engineering efforts. This design approach allowed the team to define a system solution quickly and minimized the need for extensive vehicle level testing. The result of this approach was the development of an engine cooling system that adequately controls air, oil and coolant temperatures during all driving and environmental conditions.

BlueStar Advanced Technology Corporation (BATC) as part of its participation in the USAF/NASA Li Ion Battery Development Consortium has developed a candidate 25-Ah cell for the Mars 2001 Lander. Although the capacity and cycle life requirements for this application are relatively modest, the low temperature performance (−20°C) and pulse discharge requirements (60A) are somewhat more challenging. Geometric requirements within the spacecraft also constrain the cell design leading to a cell with an aspect ratio quite different from those 25-Ah Li ion cells previously developed by BATC. The design of this cell and its compliance with the performance requirements of the mission will be discussed.

This paper describes the set-up and testing of a single cylinder 25cc, air cooled, 4-stroke Spark Ignition (SI) engine converted to run in Homogeneous Charge Compression Ignition (HCCI) mode with the aid of various combustion control systems. The combustion control systems were investigated regarding their effects on combustion stability and heat release phasing. Engine operation was compared with unique findings from previous work done on a very small 2-stroke HCCI engine. HCCI engine operation was possible between 1000 - 4000 rpm when using Diethyl Ether (DEE) as the test fuel. Maximum operational fuel-air equivalence ratio (Φ) was 0.75 when operating without Exhaust Gas Recirculation (EGR). This relatively high equivalence ratio was attainable due to thermal gradients induced by the high surface area to volume ratio of the small engine combustion chamber, resulting in high chamber heat transfer.

Manufacturers of heavy-duty diesel engines are facing increasingly stringent, emission standards. These standards have motivated new research efforts towards improving the performance of diesel engines. The objective of the present program is to develop a comprehensive analytical model of the diesel combustion process that can be used to explore the influence of design changes. This will enable industry to predict the effect of these changes on engine performance and emissions. A major benefit of the successful implementation of such models is that engine development time and costs would be reduced through their use. The computer model is based on the three-dimensional KIVA-II code, with state-of-the-art submodels for spray atomization, drop breakup / coalescence, multi-component fuel vaporization, spray/wall interaction, ignition and combustion, wall heat transfer, unburned HC and NOx formation, and soot and radiation.

Ever increasing specific power of diesel engines has put huge demand on effective thermal management of the pistons for the desired reliability and durability. The piston temperature control is commonly achieved by injecting cooling oil into piston galleries, but the design of the cooling system as well as the boundary conditions used in FEA simulations have so far relied mostly on empirical methods. A numerical procedure using 3D computational fluid dynamics (CFD) has therefore been developed to simulate the cooling process and to estimate the cooling efficiency of gallery. The model is able to predict the detailed oil flow and heat transfer in gallery, of different designs and engine applications, under dynamic conditions. The resulted spatially resolved heat transfer coefficient from the CFD model, with better accuracy, enables improved prediction of piston temperature in finite element analysis (FEA).

The thermal performance of an engine coolant system is efficient when the engine head temperature is maintained within its optimum working range. For this, it is desired that air should not be entrapped in the coolant system which can lead to localized hot spots at critical locations. However, it is difficult to eliminate the trapped air pockets completely. So, the target is to minimize the entrapped air as much as possible during the coolant filling and deaeration processes, especially in major components such as the radiator, engine head, pump etc. The filling processes and duration are typically optimized in an engine test stand along with design changes for augmenting the coolant filling efficiency. However, it is expensive and time consuming to identify air entrapped locations in tests, decide on the filling strategy and make the design changes in the piping accordingly.

A 3-D numerical analysis model of transient heat transfer among the multi-component coupling system in combustion chamber of internal combustion engine has been developed successfully in the paper. The model includes almost all solid components in combustion chamber, such as piston assembly, cylinder liner, cylinder head gasket, cylinder head, intake valves and exhaust valves, etc. With two different coupling heat transfer modes, one is the lubricant film heat conduction between two moving components, another is the contact heat conduction between two immovable solid components, and with the direct coupled-field analysis method of FEM, the heat transfer relation among the components is established. The simulation result dedicates the transient heat transfer process among the components such as moving piston assembly and cylinder liner, moving valves and cylinder head. The effect of cylinder head gasket on heat transfer among the components is also studied.

A three-dimensional model is used to compute the flow,sprays and combustion in a stratified-charge rotary engine. Wall temperatures estimated from available measurements are used as boundary conditions for the energy equation. The computations provide local and instantaneous heat fluxes on the rotor and the rotor housing. The instantaneous heat fluxes are integrated in time over one cycle of the rotor to obtain estimates of local cycle averaged heat flux through the rotor and the rotor housing. These are then used as boundary conditions in a thermal analysis of the rotor and rotor housing with known coolant-side flow rates and heat transfer coefficients. The thermal analysis is done using a finite-element three-dimensional code which provides updated estimates of the rotor and rotor housing wall temperatures. These wall temperatures agree within ±20°C of the measured wall temperatures.

In order to use modeling as a predictive tool for real-world particulate filter designs (segmented filters, non-axisymmetric designs), it is necessary to develop reliable 3-dimensional models. This paper presents a 3 d modeling approach, which is validated against engine-bench measurements with both FBC and CDPF systems. Special emphasis is given to the prediction of the transient inlet flow distribution, which is realized without resorting to external CFD software. The experimental and modeling results illustrate the 3-d nature of the problem, induced by the heat capacity and conductivity effects of the cement layers. It is possible to predict the localization of regeneration in certain areas of the filter (partial regeneration), as a result of poor heat transfer to thermally isolated regions in the filter. The accuracy of the model was validated by extensive comparisons with temperature measurements in 30 positions inside the filters and at various operating conditions.

CuO-water nanofluids was utilized as heat transfer medium in the cooling system of the diesel engine. By using CFD-Fluent software, for 0.5%, 1%, 3% and 5% mass concentration of nanofluids, 3-dimensional numerical simulation about flow and heat transfer process in the cooling system of engine was actualized. According to stochastic particle tracking in turbulent flow, for solid-liquid two phase flow discrete phase, the moving track of nanoparticles was traced. By this way, for CuO nanoparticles of different mass concentration nanofliuds in the cooling jacket of diesel engine, the results of the concentration distribution, velocity distribution, internal energy variation, resident time, total heat transfer and variation of total pressure reduction between inlet and outlet were ascertained.

The scope of this Standard is the definition of the response of a numerically controlled machine to a valid sequence of records made up of 32 bit binary words or ASCII text strings. The Standard defines the structure of these records and of the 32 bit binary words or ASCII text strings which make up the records. This standard addresses the control of machines capable of performing 2, 3, 4, and 5 axis motion of an active tool (mill, laser, pen, etc.) relative to a part, and those capable of 2 and 4 axis tool motion relative to a rotating part (turning machines), including parallel tool slide sets capable of concurrent (merged) motion.

The present work deals with the 3-D, transient, system level CFD simulation of an automotive coolant system using a 3D CFD solver Simerics MP+®. The system includes actual CAD of radiator, cooling jacket, coolant pump, bypass valve and thermostat valve. This work is in continuation of the work done by Srinivasan et al. [1] where wax melting, conjugate heat transfer, Fluid Structure Interaction (FSI) of the valve had been solved. Thermostat valve was controlled by wax phase change model which also incorporates the hysteresis effect of wax melting and solidification. The previous work dealt with the simulation of complete cycle, opening, and closing of the thermostat valve system. Besides the physics considered in the previous study, the current model also includes the treatment of cavitation to account for the presence of dissolved gases and vaporization of the liquid coolant.

Designing an efficient vehicle coolant system depends on meeting target coolant flow rate to different components with minimum energy consumption by coolant pump. The flow resistance across different components and hoses dictates the flow supplied to that branch which can affect the effectiveness of the coolant system. Hydraulic tests are conducted to understand the system design for component flow delivery and pressure drops and assess necessary changes to better distribute the coolant flow from the pump. The current study highlights the ability of a complete 3D Computational Fluid Dynamics (CFD) simulation to effectively mimic a hydraulic test. The coolant circuit modeled in this simulation consists of an engine water-jacket, a thermostat valve, bypass valve, a coolant pump, a radiator, and flow path to certain auxiliary components like turbo charger, rear transmission oil cooler etc.

A 3D computer model named AIPAC (Aircraft Ice Protection Analysis Code) suitable for thermal ice protection system parametric studies has been developed. It was derived from HASPAC, which is a 2D anti-icing model developed at Wichita State University in 2010. AIPAC is based on the finite volumes method and, similarly to HASPAC, combines a commercial Navier-Stokes flow solver with a Messinger model based thermodynamic analysis that applies internal and external flow heat transfer coefficients, pressure distribution, wall shear stress and water catch to compute wing leading edge skin temperatures, thin water flow distribution, and the location, extent and rate of icing. In addition, AIPAC was built using a transient formulation for the airfoil wall and with the capability of extruding a 3D surface grid into a volumetric grid so that a layer of ice can be added to the computational domain.

A large amount of heat is generated in electric vehicle battery packs during high rate charging, resulting in the need for effective cooling methods. In this paper, a prototype liquid cooled large format Lithium-ion battery module is modeled and tested. Experiments are conducted on the module, which includes 31Ah NMC/Graphite pouch battery cells sandwiched by a foam thermal pad and heat sinks on both sides. The module is instrumented with twenty T-type thermocouples to measure thermal characteristics including the cell and foam surface temperature, heat flux distribution, and the heat generation from batteries under up to 5C rate ultra-fast charging. Constant power loss tests are also performed in which battery loss can be directly measured.

The paper will model a welding process as a moving heat source through the work piece and investigate the effectiveness of various pre-heating mechanisms, including moving heat sources and the thermal strips. The reduction of thermal conductivity in the material around the tool due to rising temperature will be considered in the study. The paper represents an initial attempt to develop a nonlinear, time-discontinuous, p-version Galerkin method for the study of thermal effects in the Friction Stir Welding (FSW) process. Numerical results and the topics for further studies are presented.

The vehicle Heating, Ventilation and Air conditioning (HVAC) system is designed to meet both the safety and thermal comfort requirements of the passengers inside the cabin. The thermal comfort requirement, however, is highly subjective and is usually met objectively by carrying out time dependent mapping of parameters like the velocity and temperature at various in-cabin locations. These target parameters are simulated for the vehicle interior for a case of hot soaking and its subsequent cool-down to test the efficacy of the AC system. Typically, AC performance is judged by air temperature at passenger locations, thermal comfort estimation along with time to reach comfortable condition for human. Simulating long transient vehicle cabin for thermal comfort evaluation is computationally expensive and involves complex cabin material modelling.

Mild hybridisation, using a 48 V system architecture, offers fuel consumption benefits approaching those achieved using high-voltage systems at a much lower cost. To maximise the benefits from a 48 V mild-hybrid system, it is desirable to recuperate during deceleration events at as high a power level as possible, whilst at the same time having a relatively compact and low cost system. This paper examines the particular requirements of the battery pack for such a mild-hybrid application and discusses the trade-offs between battery power capabilities and possible fuel consumption benefits. The technical challenges and solutions to design a 48 V mild-hybrid battery pack are presented with special attention to cell selection and the thermal management of the whole pack. The resulting battery has been designed to achieve a continuous-power capability of more than 10 kW and a peak-power rating of up to 20 kW.

The transition towards More Electric Aircraft (MEA) architectures has challenges relating to integration of power electronics with the starter generator system for on-engine application. To efficiently operate the power electronics in the hostile engine environment at high switching frequency and for better thermal management, use of silicon carbide (SiC) power devices for a bi-directional power converter is examined. In this paper, development of a 50 kVA bi-directional converter operating at an ambient temperature of about 2000C is presented. The design and operation of the converter with details of control algorithm implementation and cooling chamber design are also discussed.

As a part of a program jointly supported by the USAF and Canada's Department of National Defense, BlueStar is developing large (50 to 100-Ah)lithium ion cells for aircraft and spacecraft applications. Presently, 20-Ah cells are being developed as the first stage of the scale-up process and the design of these cells involves several tradeoffs related to the specific nature of this application. This paper will present the design of this first generation cell in the context of these tradeoffs as well as presenting the results of the performance and life testing of these cells.