Automotive Science and Engineering

---

In this article, rubber bumpers of Double - Wishbone suspension system have been modeled and analyzed. The objective of the present work is to predict the performance of these products during deformation, represent an optimum method to design, obtain stiffness characteristic curves and utilize the results in the automotive suspension dynamic analysis. These parts are nonlinear and exhibit large deformation under loading. They have an important role to limit the motion of wheels and absorb energy. In this study, nonlinear FE model using ABAQUS software was used to obtain the bumper load - displacement curve. Then a laboratory test was done on the bumper to get this curve. The comparison between numerical and experimental results shows a good adaptation. A less than 2 percent difference has been observed between them. Thus, we can use this numerical method to simulate bumpers easily and accurately.

---

Multidimensional modelling of open-cycle process of OM355 engine was developed. Calculations for computational mesh were carried out. The results of the model were validated by experimentally measured in-cylinder pressure and the good agreement between calculations and measurements approved the trustworthy of numerical code. Results included pressure, temperature, emission and Rate of heat release diagrams were represented for the full cycle. Further more local flow field velocity vectors were indicated. The results show the importance of open-cycle simulations in automotive researches.

---

---

This paper develops an automatic parking algorithm based on a fuzzy logic controller with the vehicle pose for the input and the steering angle for the output. In this way some feasible reference trajectory path have been introduced according to geometric and kinematic constraints and nonholonomic constraints to simulate motion path of car. Also a novel method is used for parking space detection according to image processing. A fuzzy controller according to experiments of skilled driver and path planning is designed, and then fuzzy rules are tuned and finally fuzzy membership functions are optimized using genetic algorithm. Simulation results illustrate the effectiveness of the developed schemes

---

In the present paper, a complete literatures review of thermal barrier coating applications in diesel engines is performed to select a proper type and to find coating effects. The coating system has effects on the fuel consumption, the power and the combustion efficiency, pollution contents and the fatigue lifetime of engine components. Usually there are several beneficial influences by applying ceramic layers on the combustion chamber, including the piston, the cylinder head, the cylinder block, intake and exhaust valves by using a plasma thermal spray method. Several disadvantages such as producing nitrogen oxides also exist when a coating system is used. In this article, all effects, advantages and disadvantages of thermal barrier coatings are investigated based on presented articles.

---

The objective of this study was to develop a numerical model for the prediction of temperature distribution, effective plastic strain distribution, and especially material flow in friction stir welding of copper plates. The DEFORM-3D software was used by incorporating a lagrangian incremental formulation. Threedimensional results of the material flow pattern which were extracted using the point tracking are in good agreement with the experiment. It was shown that the main part of material flow occurs near the top surface. Material near the top surface at the behind of tool stretches from retreating side towards advancing side which leads to non-symmetrical shape of the stir zone. The stir zone shape in FSW of copper alloys, which was predicted by simulation, does not lean completely towards any sides of welding line.

---

In the present work, multidimensional modeling of open-cycle process of OM355 engine was developed. Calculations for computational mesh were carried out. The results of the model were validated by experimentally measured in-cylinder pressure and the good agreement between calculations and measurements approved the trustworthy of numerical code. Results included pressure, temperature, emission and Rate of heat release diagrams were represented for the full cycle. Furthermore local flow field velocity vectors were indicated. The results show the importance of open-cycle simulations in automotive researches.

---

The directional response and roll stability characteristics of a partly filled tractor semi-trailer vehicle, with cylindrical tank, are investigated in various maneuvers. The dynamic interaction of liquid cargo with the tractor semi-trailer vehicle is also evaluated by integrating a dynamic slosh model of the partly filled tank with five-degrees-of-freedom of a tractor semi-trailer tank model. The dynamic fluid slosh within the tank is modeled using three-dimensional Navier-Stokes equations, coupled with volume-of-fluid equations and analysed using the FLUENT software. The coupled tank-vehicle model is subsequently analysed to determine the roll stability characteristics for different maneuvers. The results showed the interaction of fluid slosh with vehicle's dynamic. Another findings of this investigation also revealed that the roll stability of a tractor semi-trailer tank carrying liquid was highly affected by fluid sloshing and caused degradation of roll stability in comparison with vehicle carrying rigid cargo.

---

Nowadays, the use of small vehicles is spreading among urban areas and one sort of these vehicles are three-wheeled vehicles (TWVs) which can be competitive with four-wheeled urban vehicles (FWVs) in aspects such as smallness, simple manufacturing, and low tire rolling resistance, fuel consumption and so on. The most critical instability associated with TWVs is the roll over. In this paper a tilt control mechanism has been modeled which can reduce the danger of roll over by leaning the vehicle towards the turning center in order to decrease the amount of lateral load transfer (LLT), and by doing so, system combines the dynamical abilities of a passenger car with a motorcycle. A 3 degree of freedom vehicle model is simulated at constant speed in MATLAB-Simulink environment and a fuzzy algorithm is developed to control such a non-linear system with appropriate tilting torque. Results are interpreted in presence and absence of controller with different longitudinal speeds and steering inputs the results are also compared to behavior of a similar FWV and this is concluded that the tilt control system could countervail deficiencies of the TWV compared to the FWV.

---

In the present paper, the modal analysis on a full finite element model of an off-road vehicle. This vehicle was modeled in the CATIA software and then meshed in the HYPERMESH software. The free vibration analysis was conducted by the ABAQUS software. By applying an external displacement, the forced vibration analysis was also performed. As a result, natural frequencies and shape modes were extracted to detect critical regions. Then, some improvements were suggested to have better vibration behavior of the vehicle.

---

Dual turbocharger turbine is fed by an unequal out-of-phase mass flow charge almost all the time which have significant effects on its performance parameters and flow phenomena which are not well known. Besides fully understanding the flow behavior in the radial turbine suffers from lack of detailed information about the secondary flows. This article studies the secondary flow structure within a dual entry turbine in different admission conditions. Results showed that with increasing the inequality of pressure ratio in the entries, performance of the turbine significantly decrease. From the results a profoundly disturbed flow in the interspace region was recognized. The pressure distribution of each limb shows some dependency between entries. To fully understand the flow physics, the 3D computational fluid dynamics (CFD) was implemented and compared with the experimental results of Copeland et al. (2010). The results are used to study the physical origin and the effect of nonuniform mass flow on secondary vortices. The generation and the development of the inflow, horseshoe and the corner vortex was investigated by evaluating contour plot of velocity distribution. Results demonstrated that the inflow vortex is due to the asymmetrical flow into the passage from the volute.

---

Drying temperature of the flux at normal atmosphere has a crucial role in brazing quality in automotive aluminum-based heat exchangers. Over the course of this research, NOCOLOK^® flux consists of two phases of K₂AlF₅.H₂O and KAlF₄ with melting point around 580 °C was used. A flux slurry was applied on the base metal, and dried at 220, 300 and 380 °C in air. Mechanical assessment revealed that when flux dried at 300 °C, the joint withstands maximum shear stress of 44 MPa with complete bonding. At 220 °C and 380 °C, joint shear stresses are 34 MPa, 30 MPa respectively. 380 °C dry-off temperature under nitrogen gas improved shear strength to 39 MPa. Taking dry-off temperature as 300 °C the amount of defective heat exchangers was reduced from 6% to 2% on a daily basis.
 

---

---

High-entropy oxides (HEOs) are single-phase crystal structures composed of multiple metal elements that provide great potential for energy storage applications due to the synergistic effect of various metal species. They are considered effective anode materials for high-performance lithium-ion batteries (LIBs) because of their structural stability, high electronic conductivity, and ability to create anode materials with novel structures using several elemental compounds. Because the effects of different types of electrochemically active elements on the properties of anode materials are unknown, it is necessary to develop HEOs and investigate their properties. Herein, to explore the electrochemical properties of HEOs by changing the content of cations with various mechanisms for storing lithium, we prepared three samples of HEOs with spinel structure using the solid-state method, one of which is equimolar ((MgNiTiFeZn)_0.6O₄) and two numbers are near-equimolar ((Mg_0.6Ni_0.6Ti_0.3Fe_0.9Zn_0.6)O₄ and (Mg_0.6Ni_0.6Ti_0.3Zn_0.9Fe_0.6)O₄)). For structural properties determination, X-ray diffraction analysis was used. The results confirmed the formation of three single-phase high-entropy oxides.
Electrochemical tests indicated the structural stability of three compounds of high entropy oxides, and the composition of (MgNiTiFeZn)_0.6O₄, relative to the others, has better rate capability (163 mAhg⁻¹ at 1000 mAg^–1) and higher discharge capacity (220 mAhg⁻¹ at 200 mAg^–1) after 200 cycles.