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The Army's approach to Test, Training and Evaluation (TT&E) is undergoing dramatic changes. In particular, the rapid transition to incorporate modeling and simulation into life cycle development is mandating new approaches to testing and experimentation. Versatile Information System - Integrated, On-line, Nationwide (VISION) a holistic information collection, dissemination, and management system which employs a web-centric approach that merges and fully exploits instrumentation, information management, and networking technologies to addresses these challenges. This paper describes the VISION architecture.

The paper presents the speed control analysis for a turbocharged engine by simulation using block diagram type of modeling and solving the differential equations using both fourth order Runge-Kutta and transfer function methods using various combinations of proportional, integral and differential coefficients in a PID controller with application of various types of oscillating loads. The simulation results show that the governor using PID control provides the best control of engine speed and the optimum values of these coefficients are different for different operating conditions having different amplitude and frequency of load fluctuations. The Runge-Kutta method is found to give more accurate results but takes more computer time.

This paper describes the features and use of the commercial multibody simulation program ADAMS (Automatic Dynamic Analysis of Mechanical Systems) in the simulation of tracked vehicle applications. In detail is discussed the features of how the add-on toolkit ADAMS/Tracked Vehicle (ATV) can be used for building, maintaining and simulating tracked vehicle models.

This investigation was concerned with the rate of heat transfer from the working gases to the combustion chamber walls of the internal combustion engines. The numerical formula for estimating the heat transfer to the combustion chamber wall was derived from the theoretical analysis and the experiment, which were used the constant volume combustion chamber and the actual gasoline engine. As a result, mean heat transfer in the internal combustion engine becomes possible to estimate with measuring the cylinder pressure. In addition, the derived numerical formula forms with quite simple variables. Therefore it is very useful for engine design.

In the catalytic converter, the thermal conductivity of the insulation material (intumescent mat) placed between the ceramic catalyst and the metal shell is strongly dependent on the temperature, resulting in the solving of non-linear heat conduction equations. In this paper, the analytic solution for the steady heat flow in a cylinder with temperature dependent conductivity is given. Using this analytic solution for the mat and including convection and radiation at the converter skin, an analytical expression for calculating converter skin temperature is obtained. This expression can be easily incorporated in a Fortran code to calculate the temperatures.

Warming-up time should be reduced to prevent mechanical wear and to get available full power as soon as possible. Going out from a warm parking condition to the cooler outside produce a unnecessary cooling of water and engine housing that impairs warming-up time. Short runs after long stops of engines (taxis for example), could cause engine to work below its advisable temperature level. Other situations like long descents in mountains under cold weather conditions make the engine temperature fall below its warming-up temperature level. The present invention (patent application number: P9802592) is a anti-cooling system, which only works in these situations, uses already existing devices in vehicular water cooled engines, like electric dc-motor and radiator fan, and drives them by means a small electronic controller. The controller senses the possibility of saving engine heat (while cooling water temperature is below an appropriate level).

With the increasing efficiency of D.I. Diesel engines, the heat power needed to warm the passengers compartment becomes too low during the warm-up period. So the temperature increase of oil and water may be accelerate. This paper is devoted to the understanding of the phenomena involved in this process and their modeling. A diesel engine enclosed in a calorimeter is mounted on a test bench and largely instrumented. From the recorded data, the instantaneous energy balance is set up for different running conditions. Some general trends may be pointed out. During the first minute, 50% of the fuel energy is absorbed by the heat capacity of the heavy metallic components. This part progressively decreases to the benefit of heat transferred to the coolant. Furthermore, for increasing distance from the combustion chamber in the block, the rate of temperature rise decreases. Concerning the oil temperature evolution, it lags behind the water one.

CFD analysys with automatically generated mesh has been carried out by tetrahedral cells. This type of Computational Fluid Dynamics (CFD) method requires larger number of cells compared to those based on hexahedral cells. Also its cell arrangement on the wall is important to get correct wall friction effect in case wall function model is used. The purpose of this study is to investigate the influence of tetrahedral and prismatic cell size and thickness on the pressure loss and the heat transfer coefficient in the case of engine intake duct and coolant flow CFD. We found the prismatic cell thickness and layer number on wall has improved Y+ distribution and pressure drop accuracy at intake duct. Also heat transfer coefficient of coolant flow simulation accyracy is improved. We carried out automatic mesh generation and high speed computing by Windows personal computer.

A robust nonlinear meshfree computer-aided-engineering (CAE) analysis algorithm based on the Reproducing Kernel Particle Method (RKPM) is employed for simulating the installation and sealing performance of a truck-based radiator hose/fitting/clamp system assembly. The formulation of the present nonlinear meshfree CAE simulation comprises the geometric and material nonlinearities, a Lagrangian material based reproducing kernel shape function, a pressure projection method for nearly incompressible rubber hose material, and a direct transformation method for frictional contact boundary conditions. This simulation, which defines a radiator hose/fitting operating process series as insertion, clamping, pressurization and pull-off, provides a parametric investigation on the effect of clamping depth, clamping width, clamping location, and fluid pressure load on the hose-fitting contact seal width, contact pressure distribution, and the maximum pull-off force properties.

In the analysis of a cooling network, Computational Fluid Dynamics methods show an unquestionable usefulness. Nevertheless, this approach is largely limited for simulating the behavior of multidisciplinary components connected in a system. The lumped parameter approach suits these systems simulation. This awareness has led to the development of methods for structuring these kinds of problems. Applying the multiport method, the Thermal, Thermal-hydraulic and Cooling system libraries were created. These libraries comprise a set of basic and specific components from which it is easy to model large thermal-hydraulic and engine cooling networks. These basic and specific elements facilitate the study of phenomena whose knowledge is indispensable for the analysis of a whole system. An application of these libraries to a RENAULT car is presented.

The modeling of thermal phenomena in transient state in a vehicle, typically the studies of heat exchanges in the engine or the heat exchange in the exhaust line leads to the use of nodal methods or lumped parameters in systems approach. This lumped parameters vision has led to important formalization studies these past years leading to two important concepts: the multiport concept of which bond-graphs constitute the theoretical framework, and the polymorphic modeling concept leading to the definition of a minimum of basic elements allowing to build a maximum of situations. This article proposes to demonstrate how these concepts have been used to bring about the development of a library of basic elements. Its application is demonstrated by the modeling of the different modules composing the engine (lubrication, cooling, exhaust and metal masses).

One-dimensional ‘wave-action’ codes are widely used by internal combustion engine manufacturers. However, the modelling of multi-pipe junctions within such simulations presents a problem, since the geometry of the junctions cannot be represented fully using a one-dimensional approach, and it can produce a strongly directional effect on the propagated waves. ‘Pressure-loss’ models of junctions have been devised as boundary conditions for one-dimensional simulations, these allow the some geometry induced effects to be introduced into the calculation. This paper examines the performance of such models, when used to simulate a pulse converter-type junction, under unsteady flow conditions.

In Diesel engines equipped with jerk injection pumps there appear many effects derived from fuel compressibility and the short duration of injection. As a result of them, cavitation, secondary injection, dribble and other hazardous phenomena may occur. With the objective of studying these processes, a simulation model for an indirect Diesel injection system has been developed. The mathematical model takes into account cavitation and gas dissolved effects. A relationship is obtained theoretically to reproduce the dependence of density of fuel oil with the pressure. The deduction of this equation is based on some hypotheses: that the amount of air in the liquid is constant, the process isothermal, the liquid fuel and its vapour are in thermodynamic equilibrium, and finally, that the temperature, pressure and velocity of both phases are identical. The unidimensional two-phase flow equations are simplified and employed to resolve the high-pressure line.

This work presents the development, validation and use of a SIMULINK integrated vehicle system simulation composed of engine, driveline and vehicle dynamics modules. The engine model links the appropriate number of single-cylinder modules, featuring thermodynamic models of the in-cylinder processes with transient capabilities to ensure high fidelity predictions. A detailed fuel injection control module is also included. The engine is coupled to the driveline, which consists of the torque converter, transmission, differential and prop shaft and drive shafts. An enhanced version of the point mass model is used to account for vehicle dynamics in the longitudinal and heave directions. A vehicle speed controller replaces the operator and allows the feed-forward simulation to follow a prescribed vehicle speed schedule.

To evaluate improvements in engine behaviour, particularly with regard to engine management or aftertreatment systems, the engine should be operated in a representative vehicle over a standardised drivecycle. To achieve partial validation in an engine dynamometer test cell, the project described in this paper implements a driver and vehicle simulation which controls, in closed loop, a physical engine, clutch and dynamometer combination. The vehicle can be modelled with either a manual or automatic transmission, and package is implemented in the Matlab/dSPACE rapid prototyping environment

The goal of this paper is to obtain a simple fast model that provides information about the spray tip penetration (for free and wall jet), droplets velocity distribution and fuel concentration distribution. This model would be an important first step in the construction of a simple model capable to provide online information about the spray behaviour in engine conditions, although for the moment, the model only concerns cold sprays. As this model is based in momentum and mass flux conservation, and the patterns observed in gaseous turbulent jets, its agreement with experimental Diesel results will help to improve understanding of the spray structure in terms of the similarities and differences with a gas jet, as well as of the importance of the spray front structure in its penetration.

During the last years a great deal of effort has been made for the reduction of pollutant emissions from direct injection Diesel Engines. Towards these efforts engineers have proposed various solutions, one of which is the use of gaseous fuels as a supplement for liquid diesel fuel. These engines are referred to as dual combustion engines i.e. they use conventional diesel fuel and gaseous fuel as well. The ignition of the gaseous fuel is accomplished through the liquid fuel, which is auto-ignited in the same way as in common diesel engines. One of the fuels used is natural gas, which has a relatively high auto-ignition temperature. This is extremely important since the CR of most conventional diesel engines can be maintained. In these engines the released energy is produced partially from the combustion of natural gas and from the combustion of liquid diesel fuel.

Catalytic converters are typically constrained and cushioned by an intumescent mat material that is critical to the durability of the ceramic and metallic substrates. In an effort to reduce costs and improve designs, this work attempts to develop and verify a material model for the mat that can be utilized in predictive analysis. Test data are used in conjunction with the finite element program ABAQUS™ to create both a hyperfoam and a user-defined material model. These models will be verified and compared by modelling with ABAQUS the specimens and test conditions used to generate the data.

A typical automotive catalytic converter is constructed with a ceramic substrate and a steel shell. Due to a mismatch in coefficients of thermal expansion, the steel shell will expand away from the ceramic substrate at high temperatures. The gap between the substrate and shell is usually filled with a fiber composite material referred to as “mat.” Mat materials are compressed during assembly and must maintain an adequate pressure around the substrate under extreme temperature conditions. The container deformation measurement procedure is used to determine catalytic converter shell expansion during and after a period of hot catalytic converter operation. This procedure is useful in determining the potential physical durability of a catalytic converter system, and involves measuring converter shell expansion as a function of inlet temperature. A post-test dimensional measurement is used to determine permanent container deformation.

In this study quantitative techniques were established to assess the low temperature durability of commercially available mat systems. A new low temperature dynamic resistive thermal exposure (LT-RTE) test method was developed. The mats were evaluated in thermal cycling with maximum substrate skin temperatures from 280°C to 450°C. Results indicate that at low use temperatures the residual shear strength of the mat fell to ∼5-15KPa following 280°C cycling. Under the same LT-RTE exposure conditions an equivalent mat system, following thermal preconditioning to 500°C for 3 hours, possessed a residual shear strength of ∼30KPa. An alternative mat system with a lower shot content fiber was also evaluated, following the same thermal preconditioning previously described. This alternative mat was found to exhibit substantially higher residual shear strengths following LT-RTE aging. A residual shear strength of ∼95KPa was observed for this alternative mat following 280°C LT-RTE aging.