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Extensive research has been performed for on-board hydrogen generation, such as pyrolysis of metal hydrides (e.g., LiH, MgH₂), hydrogen storages in adsorption materials (e.g., carbon nanotubes and graphites), compressed hydrogen tanks and the hydrolysis of chemical hydrides. Among these methods, the hydrolysis of NaBH₄ has attracted great attention due to the high stability of its alkaline solution and the relatively high energy density, with further advantages such as moderate temperature range (from -5°C to 100°C) requirement, non-flammable, no side reactions or other volatile products, high purity H₂ output. The H₂ energy density contained by the system is fully depend on the solubility of the complicated solution contains reactant, product and the solution stabilizer. In this work, an approach based on thermodynamic equilibrium was proposed to model the relationship between the solubility of an electrolyte and temperature, and the effect of another component on its solubility.

The promise of thermo-electric (TE) technology in vehicles is a low maintenance solid state device for power generation. The Thermo-Electric Generator (TEG) will be located in the exhaust system and will make use of an energy flow between the warmer exhaust gas and the external environment. The potential to make use of an otherwise wasted flow of energy means that the overall system efficiency can be improved substantially. One of the barriers to a successful application of the technology is the device efficiency. The TE properties of even the most advanced materials are still not sufficient for a practical, cost effective device. However the rate of development is such that practical devices are likely to be available within the next fifteen years. In a previous paper [ 1 ], the potential for such a device was shown through an integrated vehicle simulation and TEG model.

The established method of clearing a misted car windshield or of maintaining a clear view under misting conditions is through the application of an air supply via jet outlets in the instrument panel. The ability of such arrangements to perform adequately is a function of the prevailing environmental conditions, the vehicle speed, the condition of the demist air source and the geometry and arrangement of the jet outlets. This paper presents experimental data obtained in a purpose built environmental chamber designed to accommodate simple rectangular jets impinging on a misted glass surface. The facility consists of three conditioned air sources applied to a test chamber designed to represent the external, internal and demist air flows. Mist conditions on the glass surface are determined using a novel technique employing a CCD camera acquiring grey scale images which are digitally analysed to generate mist detection, grading and clearing contour data.

It is generally accepted that knocking combustion influences the heat transfer in SI engines. However, the effects of heat transfer on the onset of knock is still not clear due to lack of experimental data of the thermal boundary layer close to the combustion chamber wall. This paper presents measurements of the temperature in the thermal boundary layer under knocking and non-knocking conditions. The temperature was measured using dual-broadband rotational Coherent anti-Stokes Raman Spectroscopy (CARS). Simultaneous time-resolved measurements of the cylinder pressure, at three different locations, and the heat flux to the wall were carried out. Optical access to the region near the combustion chamber wall was achieved by using a horseshoe-shaped combustion chamber with windows installed in the rectangular part of the chamber. This arrangement made CARS temperature measurements close to the wall possible and results are presented in the range 0.1-5 mm from the wall.

A naturally aspirated in-line six-cylinder 2.9-litre Volvo engine is operated in Homogeneous Charge Compression Ignition (HCCI) mode, using camshafts with low lift and short duration generating negative valve overlap. This implementation requires only minor modifications of the standard SI engine and allows SI operation outside the operating range of HCCI. Standard port fuel injection is used and pistons and cylinder head are unchanged from the automotive application. A heat exchanger is utilized to heat or cool the intake air, not as a means of combustion control but in order to simulate realistic variations in ambient temperature. The combustion is monitored in real time using cylinder pressure sensors. HCCI through negative valve overlap is recognized as one of the possible implementation strategies of HCCI closest to production. However, for a practical application the intake temperature will vary both geographically and from time to time.

The main benefit of HCCI engines compared to SI engines is improved fuel economy. The drawback is the diluted combustion with a substantially smaller operating range if not some kind of supercharging is used. The reasons for the higher brake efficiency in HCCI engines can be summarized in lower pumping losses and higher thermodynamic efficiency, due to higher compression ratio and higher ratio of specific heats if air is used as dilution. In the low load operating range, where HCCI today is mainly used, other parameters as friction losses, and cooling losses have a large impact on the achieved brake efficiency. To initiate the auto ignition of the in-cylinder charge a certain temperature and pressure have to be reached for a specific fuel. In an engine with high in-cylinder cooling losses the initial charge temperature before compression has to be higher than on an engine with less heat transfer.

Anticipating the need to improve the level of comfort for passengers in future aircraft designs, a study on the cost of providing more space for economy class seating has been conducted. Using an existing aircraft design (B777) as the baseline and British Airways published accounts it was shown that only about three extra economy ticket sales would be necessary to offset the operating cost increase associated with the larger fuselage. Franchising and carriage of cargo in the extra space was also investigated but shown to be uneconomic. The effect of aircraft size was studied by applying the analysis to a larger (MD12) and smaller (B757) aircraft. These investigations showed that provision of extra space is more advantageous for the larger aircraft but still remains economic for the smaller type. The method provides the basis for more detailed analysis in future studies.

An experimental and theoretical study of the effect of thermal barriers and catalytic coatings in a Homogeneous Charge Compression Ignition (HCCI) engine has been conducted. The main intent of the study was to investigate if a thermal barrier or catalytic coating of the wall would support the oxidation of the near-wall unburned hydrocarbons. In addition, the effect of these coatings on thermal efficiency due to changed heat transfer characteristics was investigated. The experimental setup was based on a partially coated combustion chamber. The upper part of the cylinder liner, the piston top including the top land, the valves and the cylinder head were all coated. As a thermal barrier, a coating based on plasma-sprayed Al2O3 was used. The catalytic coating was based on plasma-sprayed ZrO2 doped with Platinum. The two coatings tested were of varying thickness' of 0.15, 0.25 and 0.6 mm. The compression ratio was set to 16.75:1.

A theoretical investigation is presented concerning how the heat transfer process from the gas in the combustion chamber, burned as well as the unburned gas regions, to the walls is affected by the autoignition phenomenon in SI engines. The zonal model in ref. [1] is adapted for the calculations. The radiative heat flux during the heat release period and the heat transfer in the thermal boundary layer by convection are predicted for situations when autoignition has occurred. The cylinder wall temperature is also used as a parameter in this study. The effects of engine operating parameters such as engine speed, timing of ignition, duration time of flame propagation and the fuel parameter Research Octane Number, i.e., RON, on the heat flux to the walls have been studied. The heat release is calculated for a detailed chemical kinetic model, refs. [1, 2 and 3].

In this work, constant volume combustion is studied using a zero-dimensional FORTRAN code, which is a wide-ranging chemical kinetic simulation that allows a closed system of gases to be described on the basis of a set of initial conditions. The model provides an engine- or reactor-like environment in which the engine simulations allow for a variable system volume and heat transfer both to and from the system. The combustion chamber is divided into two zones as burned and unburned ones, which are separated by an assumed thin flame front in the combustion model used for this work. Equilibrium assumptions have been adopted for the modeling of the thermal ionization, where Saha's equation was derived for singly ionized molecules. The investigation is focused on the thermal ionization of NO as well as for other species. The outputs generated by the model are temperature profiles, species concentration profiles, ionization degree and an electron density for each zone.

The increase in computational power in recent times has led to multidimensional computational fluid dynamics (CFD) modeling tools being used extensively for optimizing the diesel engine piston design. However, it is still common practice in engine CFD modeling to use constant uniform boundary temperatures. This is either due to the difficulty in experimentally measuring the component temperatures or the lack of measurements when simulation is being used predictively. This assumption introduces uncertainty in heat flux predictions. Conjugate heat transfer (CHT) modeling is an approach used to predict the component temperatures by simultaneously modeling the heat transfer in the fluid and the solid phase. However, CHT simulations are computationally expensive as they require more than one engine cycle to be simulated to converge to a steady cycle-averaged component temperature.

Modelling of turbochargers based on steady state operating maps for turbine and compressor rotors is widely recognized to have limitations arising from flow pulsations and heat transfer effects that are not well accounted for by interpolation and extrapolation from the mapped data. With implementation of low pressure exhaust gas recirculation systems and multi-stage boosting, the inlet conditions of centrifugal compressors vary more widely than traditional single stage compression systems. Understanding the impact of the inlet conditions on irreversibilities, and therefore efficiency complements existing works on pulse flow and heat transfer effects in informing the engine modelling community. This research experimentally explores the effect of inlet pressure and temperature on the total-total efficiency of a steady flow centrifugal compressor across a range of conditions in isolation of pulse flow effects and with negligible heat transfer.

Premixed Charge Compression Ignition (PCCI), a Low Temperature Combustion (LTC) strategy for diesel engines is of increasing interest due to its potential to simultaneously reduce soot and NOx emissions. However, the influence of mixture preparation on combustion phasing and heat release rate in LTC is not fully understood. In the present study, the influence of injection timing on mixture preparation, combustion and emissions in PCCI mode is investigated by experimental and computational methods. A sequential coupling approach of 3D CFD with a Stochastic Reactor Model (SRM) is used to simulate the PCCI engine. The SRM accounts for detailed chemical kinetics, convective heat transfer and turbulent micro-mixing. In this integrated approach, the temperature-equivalence ratio statistics obtained using KIVA 3V are mapped onto the stochastic particle ensemble used in the SRM.

Flexible Printed Circuits (FPCs) have been used extensively in instrument clusters and more recently in headliners of some vehicles. Interest in large area FPCs as a replacement for traditional wiring harnesses has been propelled by the potential benefits, which include weight and space savings, ease of assembly into the vehicle, intelligence through direct mounting of electronic components, and creative design opportunities. This paper describes the development of a specification for flexible copper-clad dielectric materials to be used in the construction of a large FPC intended to replace an instrument panel wiring harness.

Numerical models are used in this study to investigate the oil flow and heat transfer in the piston gallery of a diesel engine. An experiment is set up to validate the numerical models. In the experiment a fixed, but adjustable steel plate is instrumented and pre-heated to a certain temperature. The oil is injected vertically upwards from an underneath injector and impinges on the bottom of the plate. The reduction of the plate temperature is recorded by the thermocouples pre-mounted in the plate. The numerical models are used to predict the temperature history at the thermocouple locations and validated with the experimental data. After the rig model validation, the numerical models are applied to evaluate the oil sloshing and heat transfer in the piston gallery. The piston motion is modeled by a dynamic mesh model, and the oil sloshing is modeled by the VOF (volume of fluid) multiphase model.

The present study introduces a modeling approach for investigating the effects of valve events and gas exchange processes in the framework of a full-cycle HCCI engine simulation. A multi-dimensional fluid mechanics code, KIVA-3V, is used to simulate exhaust, intake and compression up to a transition point, before which chemical reactions become important. The results are then used to initialize the zones of a multi-zone, thermo-kinetic code, which computes the combustion event and part of the expansion. After the description and the validation of the model against experimental data, the application of the method is illustrated in the context of variable valve actuation. It has been shown that early exhaust valve closing, accompanied by late intake valve opening, has the potential to provide effective control of HCCI combustion.

The use of thermo-electric (TE) generation systems in internal combustion engines (ICEs) to reduce the carbon dioxide emission by harnessing the exhaust thermal energy is showing increasing promise. In addition, integration with after treatment devices is a development route for this technology that offers a great potential. Recent work on TE systems have shown that the overall efficiency of present TE generation systems are constrained by, the limitations of the conversion efficiency and operating temperatures of TE materials; fabrication quality, durability and thermal performance of the thermo-electric modules (TEMs); geometrical configuration and heat exchange efficiency of thermo-electric generator (TEG) and; conversion techniques of the TEG's electrical output to a form suitable for vehicle systems.

A framework to study the response of seated operators to whole-body vibration (WBV) is presented in this work. The framework consists of (i) a six-degree-of-freedom man-rated motion platform to play back ride files of typical heavy off-road machines; (ii) an optical motion capture system to collect 3D motion data of the operators and the surrounding environment (seat and platform); (iii) a computer skeletal model to embody the tested subjects in terms of their body dimensions, joint centers, and inertia properties; (iv) a marker placement protocol for seated positions that facilitates the process of collecting data of the lower thoracic and the lumbar regions of the spine regardless of the existence of the seatback; and (v) a computer human model to solve the inverse kinematics/dynamic problem for the joint profiles and joint torques. The proposed framework uses experimental data to answer critical questions regarding human response to WBV.