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This paper presents the implementation of an optimal design methodology to design a heat recovery system (HRS) based on an Organic Rankine Cycle (ORC). The optimal design sought to simultaneously minimize the total volume of the system and maximize the power recovered. As a result of the application of the methodology, a family of optimal solutions with different dimensions and capacities was obtained. The implemented methodology was composed of three interacting modules. The first module corresponds to a parametric model that estimates the response of the system. The second module corresponds to a co-simulation scheme that exchanges data between the other two modules. The third module corresponds to an optimization strategy that explores the design space and finds the optimal solutions. The optimal design methodology was implemented in a case study. The case study was an HRS used to recover energy from the exhaust gases of a small car.

Currently, the heat recovery systems based on thermoelectrics are an important part of the technologies under study to improve the efficiency of vehicles with internal combustion engines. Different types of heat exchangers are used as part of the components for the operation of the heat recovery technologies. Among the heat exchangers, the heat pipes are studied due to their promising results. This work presents the experimental analysis of a heat exchanger prototype based in heat pipes. The prototype was custom designed for a given thermoelectric module. The design was performed seeking to maximize its efficiency while protecting the module by avoiding possible excesses of temperature during the operation. The requirements for the heat pipe design were defined from the experimental characterization of the thermoelectric module. The prototype was manufactured through a sintering process. The system was tested in the laboratory first by components, and then as a system.

This paper presents a feasibility analysis of the use of a thermoelectric generator for the design of a non-intrusive exhaust energy recovery system. The energy recovery system is intended to be used on a light duty vehicle with naturally aspirated internal combustion engine. The non-intrusive characteristic is proposed as an exploratory work with the aim to develop an aftermarket system. The energy source for the system is the exhaust pipe wasted heat. The analysis includes as design variables the number of thermoelectric modules and their location along the exhaust system. The characteristics under analysis are fuel consumption and payload. A numerical model is developed and used to investigate the possible design scenarios. This model is composed by three sub-models. The sub models are mean value engine model, exhaust heat transfer model, and vehicle longitudinal dynamics model. Three driving cycles are used: two standard driving cycles and a real driving cycle.

Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.

In the present paper, Computational Fluid Dynamics (CFD) simulations of the aerodynamics of a station wagon using DES (Detached Eddy Simulation), based on the Spalart-Allmaras turbulence model, are discussed and compared with experimental results. DES is a non-zonal hybrid turbulence model that uses both Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES), enabling a better equilibrium between the accurateness and the computational cost of the solution. Simulations were run in parallel using the commercial software ANSYS/FLUENT v13.0, and required a computational grid of approximately 50 million cells. Some flow characteristics such as boundary layer separation, recirculation zones, and the entire pressure and velocity field were also obtained and analyzed.

Target cascading methodology is applied to the optimization problem of the kinematics of a rack and pinion steering mechanism coupled to a double-wishbone suspension system of a hybrid off-road vehicle. This permits the partition of a complex problem into reduced order sub-problems in a hierarchical manner, leading to a more efficient design and optimization process. According to the nature of the problem, it is proposed a four level hierarchy organization. The uppermost level is the general vehicle design problem. The second level consists in various system-level design problems such as frame, powertrain and the set suspension-steering. The steering system design problem is proposed in a third hierarchical level. At the lowest level are the components design problems. The vehicle under study will work mainly under off-road condition at low speed.

Target cascading methodology is proposed as an efficient approach to the design optimization of the geometry of a double-wishbone suspension system of an off-road vehicle. The geometric setting of the suspension plays an important role on its performance, as well as on the interactions with other design domains of the overall system. In order to organize the complexity of this system, two types of hierarchies are established: a system hierarchy and a model hierarchy. For the system-based hierarchical organization, four levels were identified to express the suspension design problem in an overall vehicle design context: a super-system at the top level, two system design levels at the second and third hierarchical levels, and a components level at the lowest level. The model-based hierarchical organization considers four analysis models to investigate the suspension behavior: a steering DOF constrained kinematic model, a longitudinal, a handling and a ride dynamics model.

The target cascading methodology allows dealing with multi-domain coupled design problems. With this methodology, a complex design and optimization problem is decomposed into reduced-order problems in an ordered hierarchical structure, without losing the information about the coupling interactions between them. The order-reduction and partition of the original design problem not only bring computational advantages in the solution process, but also permit the designer to have a deeper insight of the problem nature. This work is centered in the geometric problem related to the design and optimization of a double-wishbone suspension system of an off-road vehicle. Given the nature of this problem, the target cascading methodology is proposed as an efficient solution approach. This methodology recognizes that the suspension system plays an important role in the interactions at different levels of the design problem including system dynamic response and systems physical interactions.

This work studies the dynamic simulation of mechanical components under intermediate strain rates. The study is centered on components composed of an elastomeric material and a metal reinforcement. Two different constitutive models were proposed to simulate the elastomeric material dynamic behavior. The proposed models were the Maxwell and the Cowper & Symonds models. For the components' simulation, the material characteristics were obtained through a multivariable identification process based on the experimental data acquired from a dynamic material analysis (DMA). For the generalized Maxwell model the system frequency response was analyzed, and for the Cowper & Symonds model a finite element analysis was performed. It was found that the Cowper & Symonds model implementation by finite element analysis allows a good fit of the material properties but has a high computational cost.

This work presents the dynamic characterization of an elastomeric component under intermediate strain rates. The characterization is focused in the nonlinear material's dynamic behavior, with particular attention to the influence of viscoelastic properties on the material's response. A wide experimental campaign was performed. It started with a set of tests devoted to investigate the influence of the excitation frequency on the material's mean stress for fixed strains. The material was also tested under different load conditions. The influence of the displacement and temperature was also studied. Different test modes of dynamic mechanical analysis (DMA) were used. The collected data has been used for direct analysis and it will be used as an input for constitutive models of the material. From the analysis it was found that there is an interval of temperatures in which the material under study is highly dependent to the temperature itself.

The development of vehicle navigation systems with low cost and medium uncertainty is necessary in order to perform an effective road vehicle fleet analysis. This work is a part of a project centered on the development of an integrated inertial - satellite navigation system which estimates in a very accurate way the kinematic variables of a vehicle during a set of different testing scenarios, including the development of driving cycles. A study for the uncertainty of the inertial navigation system is shown. The results provide criteria for the selection of the components of the system, including requirements on the satellite systems.

In this paper the comfort sensitivity to the variation of the inertia parameters is studied. For the theoretical approach, two computational models that predict the comfort response of a vehicle are developed and verified. These models are used to study the effect of a change on the inertial properties of the car on its comfort response. The models are developed on a commercial multi-body package and also implementing handwritten equations with a numerical integration algorithm. The influence of the inertial properties on comfort is also experimentally studied. Both approaches use two different road patterns as input generating a roll and pitch excitation. An allowed uncertainty on the inertia properties is proposed, based on the sensitivity to those properties.

The influence of the inertia properties (mass, centre of gravity location, and inertia tensor) on the dynamic behaviour of the engine-gearbox system of a car is studied in this paper, devoting particular attention to drivability and comfort. The vibration amplitudes and the natural frequencies of the engine-gearbox system have been considered. Additionally, the loads transmitted to the car body have been taken into account. Both the experimental and the theoretical simulations confirmed that the engine-gearbox vibrations in the range 10 - 15 Hz are particularly sensitive to slight variation of the inertia properties. The effects on engine-gearbox vibrations due to half-axles, exhaust system, pipes and inner engine-gearbox fluids have been highlighted.