The thermal regime of a gearbox is of considerable importance to its performance. Several significant gearbox parameters, such as the efficiency and fatigue life of its components, are temperature dependent. It is thus important to be able to determine the temperatures of the gearbox components during operation, but they are difficult to measure experimentally. A simulation model capable of predicting these temperatures would therefore be a valuable tool. The objective of this master’s thesis was to create a model capable of simulating the thermal regime of a truck gearbox during operation. To do this, mechanical losses in the gearbox, heat exchange with the surroundings, as well as heat transfer between components had to be accounted for. The model was created using the 1D simulation software LMS Imagine.Lab Amesim 14.0, and is based on a combination of mechanical and thermal networks. Details of the mechanical and thermal interactions between components are calculated using empirical and analytical formulas for mechanical losses and heat transfer. The result of the thesis is a model which can be used to simulate either real or idealised load cases, from which temperatures of gear wheels, shafts, bearings, housing and gearbox oil may be studied, as well as gearbox losses and heat transfer. Comparisons between simulated and measured gearbox efficiencies show good correlation. It is also shown that the model can predict oil temperatures which agree with in-vehicle measurements. Due to a lack of measurement data, most simulated component temperatures cannot be compared to measured values. However, temperature measurements performed for one of the gear wheels indicate that the model can be used to predict their temperature. In order to demonstrate the capabilities of the model, example results from both real and idealised load cases are presented.

<p>In the future, new challenges will occur during the product development in the vehicular industry when emission legislations getting tighter. This will also affect the truck cooling system and therefore increase needs for analysing the system at different levels of the product development. Volvo 3P wishes for these reasons to examine the possibility to use AMESim as a future 1D analysis tool. This tool can be used as a complement to existing analysis methods at Volvo 3P. It should be possible to simulate pressure, flow and heat transfer both steady state and transient.</p><p>In this thesis work a cooling system of a FH31 MD13 520hp truck with an engine driven coolant pump is studied. Further a model of the cooling system is built in AMESim together with necessary auxiliary system such as oil circuits. The model is validated using experimental data that have been produced by Volvo 3P at the Gothenburg facility.</p><p>The results from validation and other simulations show that the model gives a good picture of the cooling system. It also gives information about pressure, flow and heat transfer in steady state conditions. Further a design modification is done, showing how a change affects the flow in the cooling system.</p><p>The conclusion is that a truck cooling system can be built and simulated in AMESim. Further, it shows that AMESim meets the requirements Volvo 3P in Gothenburg has set up for the future 1D analysis tool and thereby AMESim is a good complement to the already existing analysis method.</p>

In the future, new challenges will occur during the product development in the vehicular industry when emission legislations getting tighter. This will also affect the truck cooling system and therefore increase needs for analysing the system at different levels of the product development. Volvo 3P wishes for these reasons to examine the possibility to use AMESim as a future 1D analysis tool. This tool can be used as a complement to existing analysis methods at Volvo 3P. It should be possible to simulate pressure, flow and heat transfer both steady state and transient. In this thesis work a cooling system of a FH31 MD13 520hp truck with an engine driven coolant pump is studied. Further a model of the cooling system is built in AMESim together with necessary auxiliary system such as oil circuits. The model is validated using experimental data that have been produced by Volvo 3P at the Gothenburg facility. The results from validation and other simulations show that the model gives a good picture of the cooling system. It also gives information about pressure, flow and heat transfer in steady state conditions. Further a design modification is done, showing how a change affects the flow in the cooling system. The conclusion is that a truck cooling system can be built and simulated in AMESim. Further, it shows that AMESim meets the requirements Volvo 3P in Gothenburg has set up for the future 1D analysis tool and thereby AMESim is a good complement to the already existing analysis method.

The master’s thesis deals with the Wankel rotary engines and their 1D simulations using a thermodynamic simulation software for the piston engines. The necessary steps for creation of the equivalent model of the four-stroke three-cylinder combustion engine are provided. The engine used for the validation model was Aixro XR 50. The data measured on this engine during testing were used to validate the created thermodynamic model. The discharge coefficient calculation of the intake and the exhaust ports is shown. The 11kW engine design is created using validated thermodynamic model.

The master’s thesis deals with the Wankel rotary engines and their 1D simulations using a thermodynamic simulation software for the piston engines. The necessary steps for creation of the equivalent model of the four-stroke three-cylinder combustion engine are provided. The engine used for the validation model was Aixro XR 50. The data measured on this engine during testing were used to validate the created thermodynamic model. The discharge coefficient calculation of the intake and the exhaust ports is shown. The 11kW engine design is created using validated thermodynamic model.

This research investigated the water use of different plant types in urban landscapes, nitrogen (N) and water transport in turf, and potential N leaching from urban landscapes to ground water. In the first study, three landscape treatments integrating different types of plants—woody, herbaceous perennial, turf—and putative water use classifications—Mesic, Mixed, Xeric—were grown in large drainage lysimeters. Each landscape plot was divided into woody, turf, and herbaceous perennial plant hydrozones and irrigated for optimum water status over two years, with water use measured using a water balance approach. For woody plants and herbaceous perennials, canopy cover, rather than plant type or water use classification, was the key determinant of water use relative to reference evapotranspiration (ETo) under well-watered conditions. For turf, monthly evapotranspiration (ETa) followed a trend linearly related to ETo. In the second study, water transport parameters were calibrated using an inverse simulation with Kentucky bluegrass (KBG). Subsequently, those parameters were applied to simulate water use by tall fescue (TF) and buffalograss (BG) turfgrasses using numerical modeling (Hydrus-1D). By using the calibrated soil hydraulic parameters obtained from the water transport simulation, N transport and transformation was modeled with Hydrus- 1D under different irrigation rates and different fertilization rates. Different soil texture scenarios were also simulated to demonstrate the influence of soil texture on N leaching. In the third study, the simulated N-leaching from different soil textures was integrated into a Geographic Information System (GIS) approach to estimate NO3-N leaching mass from urban turf areas. Nitrate-N leaching risks to ground water under overirrigation and overfertilization scenarios and efficient irrigation and fertilization scenarios were estimated. The results showed improvement of turf irrigation and fertilization management may decrease N-leaching significantly and greatly decrease the risk of ground water being contaminated by NO3-N leaching in the Salt Lake Valley.

Safety, performance and driving comforts are given high importance while developing modern day cars. All-Wheel Drive vehicles are exactly designed to fulfill such requirements. In modern times, human concern towards depleting fossil fuels and cognizance of ecological issues have led to new innovations in the field of Automotive engineering. One such outcome of the above process is the birth of electrical hybrid vehicles. The product under investigation is a combination of all wheel drive and hybrid system. A superior fuel economy can be achieved using hybrid system and optimized vehicle dynamic forces are accomplished by torque vectoring action which in turn provides All-Wheel Drive capabilities. Heat generation is inevitable whenever there is a conversion of energy from one form into another. In this master thesis investigation, a thermal simulation model for the product is built using 1D simulation tool AMESim and validation is done against the vehicle driving test data. AMESim tool was chosen for its proven track record related to vehicle thermal management. The vehicle CAN data are handled in MATLAB. In a nutshell, Simulation model accounts for heat generation sources, oil flow paths, power loss modeling and heat transfer phenomena. The final simulation model should be able to predict the transient temperature evolution in the rear drive when the speed and torque of motor is supplied as input. This simulation model can efficiently predict temperature patterns at various locations such as casing, motor inner parts as well as coolant at different places. Various driving cases were tried as input including harsh (high torque, low speed) ones. Simulation models like this helps Engineers in trying out new cooling strategies. Flow path optimization, flow rate, convection area, coolant pump controlling etc are the few variables worth mentioning in this regard.

This master's thesis describes a concept of Wankel type rotary engine for use in motorcycle with estimated power between 70 – 80 kW. Basic geometry parameters of rotor and ports are calculated. Power output is then checked on equivalent piston combustion engine with central crank mechanism in 1D simulation model. Rotor is designed for use with oil cooling system. Rotor is checked for safe design by static FEM analysis by applying maximum pressure found out of 1D simulation model.

The master’s thesis deals with methods of matching of a turbocharger to a combustion engine and with the analysis of their mutual cooperation. Besides a methodology of analytical determination of the appropriate size for compressor and turbine stage, there was created a thermodynamic model of an engine that is to be used as a means of propulsion for a prototype single-seater for the competition Formula Student. Post processing of real engine data measured on a dyno helped to create a parameter database that could be used for validation of the thermodynamic engine model and for deeper understanding of the system’s internal processes.

Cette thèse porte sur l’étude du dévissage spontané d’assemblages vissés, sous sollicitations dynamiques transversales. Un travail expérimental et numérique a été réalisé pour caractériser ce phénomène, dans des conditions proches de celles des assemblages réels. Une expérimentation a permis de provoquer le dévissage d’un boulon, en soumettant l’assemblage à des vibrations transversales par rapport à l’axe de la vis. Les effets de la précharge, du traitement de surface et de la disposition des vis ont été explorés. Ces résultats ont été confrontés avec ceux obtenus par un modèle numérique détaillé utilisant la méthode des éléments finis. Cependant, en raison de la complexité de la géométrie et des difficultés de modélisation à l’échelle locale, le temps de calcul est très important et peut être prohibitif pour une étude industrielle. Afin de remédier à cette difficulté, des modèles simplifiés ont été développés, l’un avec une approche par éléments finis associés à un connecteur cinématique, et l’autre par modélisation unidimensionnelle. Ces modèles simplifiés reproduisent correctement le phénomène du dévissage spontané et confirment leur efficacité en gain de temps de calcul. / This thesis focuses on the study of the self-loosening of bolted joints under transverse dynamic loads. Experimental and numerical work was carried out in order to reveal this phenomenon under conditions close to those of actual assemblies. An experiment allowed the loosening of a bolt to be caused by subjecting the assembly to transverse vibration with respect to the axis of the screw. Effects of preload, surface treatment and disposal of the screws were explored. These results were compared with those obtained by a detailed numerical model using the finite element method. However, due to the complexity of the geometry and modeling challenges at the local level, the computation time was very long and may be prohibitive for an industrial study. To remedy this problem, two simplified models were developed, one with a finite element approach associated with a kinematic connector, and one by unidimensional modeling. These simplified models correctly reproduce the self-loosening phenomenon and confirm their efficiency in terms of computation time.