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Nowadays the mains techniques to obtain Sound Power of machines and equipments are: - Sound Power obtained by Sound Pressure and - Sound Power obtained by Sound Intensity. This paper intends to compare results and show some advantages and disadvantages found during the tests. This discussion will be based on heavy-duty diesel engines and the data show different results (Δ=2dBA) comparing ISO 3744 and ISO 9614, but allow us to have a correlation factor, at least for this engine type.

Withdrawal of heat from internal combustion engines is a major concern in today's automotive industry, mainly due to material constraints and components durability. A well-designed cooling system may increase engine's reliability. In the light of this, a numerical study has been conducted to analyze the water flow inside MWM INTERNATIONAL's high-speed diesel engine. The study has been done in order to determine possible cavitation and boiling regions, which can reduce the heat transfer efficiency. The analysis was carried out with the help of computational fluid dynamics (CFD) commercial software ANSYS FLUENT®. The flow was considered to be steady-state, turbulent, with heat transfer and the fluid was treated as a single phase. For this reason, the possible cavitation and boiling regions are identified through vapor pressure and boiling temperature, respectively.

In diesel engines, the cylinder liner is one of the places more susceptible to have cavitation. The cavitation process consists in creation (vaporization) of steam bubbles of liquid, and consequence brusque disappearance (condensation) of the same ones in the liquid. When this disappearance or implosion occurs next to the liner surface provokes erosion of the same one. This phenomenon basically occurs from the liner vibration or strangulation of the water flow, that they provoke high speed of the cooling fluid (equation of Bernoulli) [1]. Along a stream line: In this paper we will analyze how the liner vibration is related to the cavitation process, what is the source and how the easiest way to solve it. The methodology used was: Crank domain analysis, Abusive test, in order to accelerate the failure reproduction, Counter measure check, by vibration analysis & validation, by abusive test.

The demand for low level emission engines increase the need for new technology development due to the necessity to fulfill legislation requirements without fuel consumption and engine performance deterioration. Diesel engine power, torque and fuel consumption are greatly influenced, among other variables, by the combustion chamber and piston bowl shape, the engine compression ratio and the shape and size of the intake and exhaust ports and valves. So, the intake port design optimization, taking into account the air mass flow and swirl are of great interest. In this sense, this work describes the procedures and results of the intake port design and optimization through CAD and CFD modeling and also with flow test bench results. It is showed the improvements in a four valve cylinder head, regarding the requirements of an Euro IV Diesel Engine.

This work develops the kinematic and dynamic analysis of a diesel engine mounted on cushions, obtaining the nonlinear equations of motion and its integration has the vibration responses of the engine. With the system response values, are simulated different position settings and characteristics of the cushions for the qualitative and quantitative evaluation of the dynamic changes occurring in the system.

This work presents the results and methodology of a dynamic durability analysis considering the interaction between crankcase and crankshaft. The approach is based on a robust mathematical model that couples the dynamic characteristics of the crankshaft and crankcase, representing the actual interaction between both components. Dynamic loadings generated by the crankshaft are transferred to the crankcase through flexible 3D hydrodynamic bearings. This methodology is referred to as hybrid simulation, which consists in the solution of the dynamics of an Elastic Multi-Body System (E-MBS) coupled with the Finite Element Methodology (FEM). For this study, it was considered an in-line 6-cylinder diesel engine used in off-road applications. The crankcase design must withstand higher loads due to new calibration targets stipulated for PROCONVE (MAR-I) emission regulations.

This Paper presents a study of weight reduction in an exhaust manifold of a four cylinders, 3.0 liters Diesel engine. The mass of the entire engine shall be reduced from the current 290kg to 260kg and many components will be redesigned focused on this target. Basically, the wall thickness and flanges of the exhaust manifold will be redesigned and reduced to a value which shall guaranties the component durability. The calculations will be made determining the life cycle of the proposed exhaust manifold, checking if no structural problems can occur. The shape and size of the ducts remain unchanged for performance purposes and no material changes will be considered for the new component.

In diesel engines, the timing system is normally composed by gears, sometimes with toothed belt and recently with chains. But for trucks and buses, vans and SUV's the most common is gears due to reliability. But this reliability can not be misunderstood with durability, other wise some gear noise can appears and this noise can be considered as a kind of failure at least in terms of comfort. The gear train can produce mainly two kinds of noise, rattle and whine, in this paper we will discuss about the whine noise. The discussion will be done based in a case with the 4.07TCE Sprint engine. Whine noise: Definition - It is a tonal gear frequency and their harmonics. [1] In this paper we will analyze how the whine noise is presented, what are the significant factors and how to deal with them. The methodology used can be seen in figure (1).

The mathematical modeling of the dynamics of a mechanical system is a powerful tool for the engineer predicts the behavior of the system. In the design of intake and exhaust valvetrains of diesel engine, the dynamic analysis of the system is essential for the proper sizing of the components. Through dynamic analysis of a 1D model using the Simulink software, this paper will describe the behavior of a valvetrain system that uses an exhaust rocker with hydraulic lifter.

Sound quality requirements have been more often used in light and heavy duty trucks market. Then, vehicle owners fell uncomfortable with rattle noise mainly at idle speed with air compressor operating in load phase. Sometimes they associate this noise as a failure, which can generate a car shop dealer claim, as well as product and company image deterioration. One option to deal with this kind of noise is to apply an anti-backlash gears. The literature shows that as we decrease the backlash the rattle is reduced too. Then, to understand the effect of this solution is mandatory before to apply into production. The object of this work is to study the vibroacoustics effects of the anti-backlash gear system regarding to the air compressor rattle noise of the MWM ACTEON 4.12TCE diesel engine. The angular displacement and velocities fluctuation of the air compressor anti-backlash gear were analyzed in order to characterize the air compressor gear rattle.

The need for braking capacity improvement has a negative impact as it increases the loads acting on the conventional brake system, increasing wear between its components and requiring a more robust design. Looking this scenario, an available option is to use the engine as a source of braking power. Some conventional engine brake systems consume the vehicle/engine inertia power through the exhaust system closing (total or partial). However, the braking efficiency of this version is limited by bouncing occurrence on the exhaust valves, generating stronger impact of valve and valve seat. The developed solution consists in creating an engine brake mechanism acting directly on the exhaust valve, achieving greater efficiency. The mechanism is based on a hydraulic actuator positioned between the exhaust rocker arm and the valve stem top.

Fracture split connecting rod has developed for commercial diesel engines for its advantage in improve engine performance and reduce production costs. Engine up rating is done as the need is arise for more energy output from the same volume of the cylinder. This connecting rod is made of high carbon micro-alloyed steel with controlled cooling and the blank is forged in one die mold and later fracture splitted. This connecting rod needs no additional rod and Cap contact face milling which means a substantial savings in Machining cost. A better contact between rod and cap improves stiffness and compatibility with crank train moving parts. This connecting rod is designed for Brake Main Effective Pressure (BMEP) 2.0 MPa and peak firing pressure of 180 bar. Analysis and optimization are done for tensile and compressive strength in both max. torque and over speed condition.

Internal combustion engine noise and vibration are major issues for car makers, and these are even more important for High-Level Pick-ups and SUV's which applies modern diesel engines. One important player in this scenario is the second-order unbalanced forces vibration produced by the conventional in-line 4-cylinder engine configurations, which leads to high-frequency excitation of vehicle's structure and consequent internal noise. This paper studies a balancer shaft solution for the mentioned engine configuration, as well as major design alternatives and development process and issues. This paper also presents an example of a balancer shaft design and development for a high speed diesel engine, as well as proposes a design/decision matrix methodology. Such methodology, which can be applied to any design or engineering case, helps design engineers make the right decision amongst different options by using a very simple and objective matrix.

This paper presents an approach in the context of intergranular corrosion process, its causes, effects and its direct relation with the Engineering, once the responsible professional shall consider the numerous losses that may be caused by this deterioration. The intergranular process of corrosion in stainless steel has been studied. A failure occurred by intergranular corrosion in service in Isolator Exhaust, which is critical to the functioning of the air diesel engine system. A microcrack was generated in the grain boundary region due the precipitation of complex carbides, which was aggravated by the working temperature. Given the working conditions of the isolator exhaust, it is suggested to replace the material AISI 304 with AISI 310, for it contains higher percentage of chromium, inhibiting intergranular corrosion occurrence.