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In applications demanding high performance under extreme conditions of pressure and temperature, a range of Mechanically Attached Fittings (MAFs) is offered by various Multinational Corporations (MNCs). These engineered fittings have been innovatively designed to meet the rigorous requirements of the aerospace industry, offering a cost-effective and lightweight alternative to traditional methods such as brazing, welding, or other mechanically attached tube joints. One prominent method employed for attaching these fittings to tubing is through Internal Swaging, a mechanical technique. This process involves the outward formation of rigid tubing into grooves within the fitting. One of the methods with which this intricate operation is achieved is by using a drawbolt - expander assembly within an elastomeric swaging machine.

Wet-sump transmissions are widely used in heavy duty and medium duty vehicles. As these transmissions do not have a dedicated forced lubrication system, it is important that the gear train, shafts, and enclosure are designed appropriately so that enough oil splashes to critical locations to ensure sufficient lubrication. The lubrication effectiveness of such transmissions can be studied through detailed tests or numerical simulations. Often, the vehicle, and therefore the transmission, encounters some severe operating conditions, such as climbing on an incline, driving downhill, etc. Studying these conditions through tests is an expensive process and this imposes the need for an analysis first approach. In this paper, the 3D multiphase Volume of Fluid (VOF) method is used to examine two such extreme cases: an 8-degree tilted installation of transmission in a vehicle, and an inclined condition of transmission during a 10-degree uphill climb.

Roots blower is a rotary positive displacement pump which operates by pumping a fluid with a pair of meshing lobes. Recent trends in automotive industry demands high power density solutions for various applications. In comparison with legacy applications, compressors for high power density applications demand continuous operation with harsher duty cycle as well as demand higher pressure ratios. Because of longer duty cycles, it will be subjected to high heat loads which will cause a rise in temperatures of timing gears, bearings, and other components within the assembly. Accurate prediction of thermal performance is critical to design a durable and efficient roots blower for high power density applications. Thermal analysis of an assembly of roots blower involves modelling of multi-physics phenomena. This paper details a coupled CFD analysis approach to predict temperatures of roots blower components and timing gear case oil. Timing gears are lubricated using wet sump lubrication.

The use of electrical contacts in aerospace applications is crucial, particularly in connectors that transmit signal and power. Crimping is a widely preferred method for joining electrical contacts, as it provides a durable connection and can be easily formed. This process involves applying mechanical load to the contact, inducing permanent deformation in the barrel and wire to create a reliable joint with sufficient wire retention force. This study utilizes commercially available Abaqus software to simulate the crimping process using an explicit solver. The methodology developed for this study correlates FEA and testing for critical quality parameters such as structural integrity, mechanical strength, and joint filling percentage. A four-indenter crimping tool CAD model is utilized to form the permanent joint at the barrel-wire contact interfaces, with displacement boundary conditions applied to the jaws of the tool in accordance with MIL-C-22520/1C standard.

With the advent of wide band gap semiconductor devices like SiC based MOSFETs/Diodes, there is a growing demand for utilizing electrical power instead of the conventional fuel-based power generation in both automotive and aerospace industry. In automotive/aerospace industry the focus on electrification has resulted in a need for sub-systems like inverters, power distribution units, motor controllers, DC-DC converters that actively utilize SiC based power electronics devices. To address the growing power density requirements for electronics in next generation product families, more efficient & reliable thermal management solution plays a critical role. The effective thermal management of the power electronics is also critical aspect to ensure overall system reliability. The conventional thermal management system (TMS) optimization targets heat sink/ cold plate design parameters like fin spacing, thickness, height etc. or sizing of the required cooling pump/fan.

Absorptive and isolating encapsulations or enclosures are commonly encountered around different noise-emitting components within the car industry. Not least for electric drive units, whose air borne noise shares often are dominant in the 2-6 kHz region, encapsulations can provide a cost and weight efficient noise abatement solution. The main constrains related to the acoustic performance when designing an encapsulation for electric drive units are surface coverage due to geometrical complexities, allowable package space (setting limits for maximum thickness of the encapsulation), weight and finally cost. The numerical simulation techniques for quantifying the acoustic performance in terms of insertion loss are challenging, since the encapsulations are partly compressed and far from homogeneous for example.

The current simulation models of EV and ICE Vehicles are well known in industry for their use in estimating the fuel economy or Range benefits because of controller calibrations and component sizing. However, there is a gap in understanding the behavior of accessories such as HVAC, power steering and other such auxiliary loads and the energy losses associated with them. Impact of thermal behavior of electronics on vehicle range also needs to be studied in detail. These kinds of studies help OEM and tier 1 manufactures in improving their design concepts significantly with minimum cost and development time. Hence, the focus of this study is on building simulation models of thermal, electrical, traction and control circuits of a typical electric vehicle. These models are then integrated, and analysis is performed to understand vehicle system level performance metrics.

Axial cooling fans are commonly used in electric vehicles to cool batteries with high heating load. One drawback of the cooling fans is the high aeroacoustic noise level resulting from the fan blades and the obstacles facing the airflow. To create a comfortable cabin environment in the vehicle, and to reduce exterior noise emission, a low-noise installation design of the axial fan is required. The purpose of the study is to investigate efficient computational aeroacoustics (CAA) simulation processes to assist the cooling-fan installation design. In this paper we report the current progress of the investigation, where the narrow-band components of the fan noise is focused on. Two methods are used to compute the noise source. In the first method the source is computed from the flow field obtained using the unsteady Reynolds-averaged Navier-Stokes equations (unsteady RANS, or URANS) model.

During the vehicle development process in the premium and luxury automotive segments an important task is the refinement of noise, vibration and harshness. Along with other attributes such as styling, drivability and vehicle dynamics it strongly influences the overall perception of the vehicle. At the same time the automotive manufacturers need to release more products faster to the market using shorter vehicle development time with reduced cost. Altogether this has increased the use of virtual models and decreased the number of test vehicles in the programs. When assembling vehicles in production there will be a natural variation, which will result in a spread in the attribute performances. When shifting towards virtual models and reduced numbers of physical test vehicles there is a higher risk that the variations in production will be neglected, leading to more customer complaints.

The generation mechanism and possible counter measures for fluid driven whistles in low Mach number flow duct networks are discussed. The vortex sound model, where unstable shear layers interact with the acoustic field and act as amplifiers under certain boundary conditions, is shown to capture the physics well. Further, for the system to actually whistle an acoustic feedback to the amplifying shear layer is also needed. The demonstration example in this study is a generalized resonator configuration with annular volumes attached to a straight flow duct via a number of small holes, perforations, around the duct’s circumference. At each hole a shear layer is formed and the acoustic reflections from the resonator volumes and the up and downstream sides provides a possible feedback to them. Not only the Helmholtz mode but also ring modes in the annular volumes provide a feedback to sustain whistles.

Noise generated by low Mach number flow in duct networks is important in many industrial applications. In the automotive industry the two most important are the ventilation duct network and the engine exhaust system. Traditionally, design is made based on rule-of thumb or slightly better by simple semi-empirical scaling laws for flow noise. In many cases, strong curvatures and local deviations from circular cross-sections are created due to outer geometry restrictions. This can result in local relatively high flow velocities and complex flow separation patterns and as a result, rule-of thumb and scaling law methods can become highly inaccurate and uncertain. More advanced techniques based on time domain modelling of the fluid dynamics equations together with acoustic analogies can offer a better understanding of the local noise generation, the propagation and interaction with the rest of the system.

The challenging problem of noise generation and propagation in automotive turbocharging systems is of real interest from both scientific and practical points of view. Robust and fast steady-state fluid flow calculations, complemented by acoustic analogies can represent valuable tools to be used for a quick assessment of the problem during e.g. design phase, and a starting point for more in-depth future unsteady calculations. Thus, as a part of the initial phase of a long-term project, a steady-state Reynolds Averaged Navier-Stokes (RANS) flow analysis is carried out for a specific automotive turbocharger compressor geometry. Acoustic data are extracted by means of aeroacoustics models available within the framework of the STAR-CCM+ solver (i.e. Curle and Proudman acoustic analogies, respectively).

The Constant Volume Sampler (CVS) is often used to dilute automotive exhaust with ambient air for measurement of emissions from light duty vehicles. A CVS is traditionally equipped with Critical Flow Venturi (CFV) to control and measure total flow. If the CVS is equipped with a Smooth Approach Orifice (SAO) to measure dilution air flow, the exhaust flow of the vehicle can be calculated as the difference between dilution and total flow. Calibration of the CVS and SAO is routinely done using ambient air, but carbon dioxide (CO2) and water vapor in diluted exhaust have an influence on the flow through the CFV. In current US emission legislation the provisions to include water vapor is added. However, if this is done then the effect of carbon dioxide (CO2) in exhaust has not been considered. Further on, when using the CVS to measure exhaust flow, only the CFV will be affected by the diluted exhaust gas composition.

Functionally graded materials enable structures to have distribution of different properties (physical, thermal, electrical, mechanical, etc.) across its volume; achievable via material/ design/ process engineering. These functionally graded materials can find an application in systems which demand localized variation or enhancement in properties in different regions of the same component. In this paper, we focus on the potential ways of designing functionally graded polymer composite structure by injection molding process. Advanced mold designs for injection molding process can be effectively used to manufacture the functionally graded structures. Innovative design approach has been explored to control the distribution of the filler content /orientation to impart distinctive properties across the cross section / geometry without affecting the bulk properties.

This work explores how fluid driven whistles in complex automotive intake and exhaust systems can be predicted using computationally affordable tools. Whistles associated with unsteady shear layers (created over for example side branches or perforates in resonators) are studied using vortex sound theory; vorticity in the shear layer interacts with the acoustic field while being convected across the orifice. If the travel time of a hydrodynamic disturbance over the orifice reasonably matches a multiple of the acoustic period of an acoustic feedback system, energy is transferred from the flow field to the acoustic field resulting in a whistle. The actual amplitude of the whistle is set by non-linear saturation phenomena and cannot be predicted here, but the frequency and relative strength can be found. For this not only the mean flow and acoustic fields needs to be characterized separately, but also the interaction of the two.

The concept of IC engine downsizing is a well-adapted industry standard, enabling better fuel conversion efficiency and the reduction of tailpipe emissions. This is achieved by utilizing different type of superchargers. As a consequence, the additional charger noise emission, at the IC engine inlet, can become a problem. In order to address such problem, the authors of this work have recently proposed a novel dissipative silencer for effective and robust noise control of the compressor. Essentially, it realizes an optimal flow channel impedance, referred to as the Cremer impedance. This is achieved by means of a straight flow channel with a locally reacting wall consisting of air cavities covered by an acoustic resistance, e.g., a micro-perforated panel (MPP). In this paper, an improved optimization method of this silencer is presented. The classical Cremer impedance model is modified to account for mean flow dependence of the optimal wave number.

Light weight structures give significant advantages to products in the Industrial sector. Component weight-saving plays a major role in improving the efficiency and performance of assembled systems. The introduction of lighter materials into products using dissimilar material joining techniques can create more weight savings and leads to lighter structures. Structural optimization is another method to optimize the material layout without affecting overall performance of the product. This paper discusses the methods to create lighter structures by the introduction of lighter materials in structures and structural optimization methods. Lighter materials are introduced in the structure using dissimilar material joining techniques. Joining processes such as thermal shrink-fit and mechanical press-fit are useful for metal to metal components. Similarly, adhesively bonded joints are useful for both metal and non-metal (plastics and composites) components.

In amorphous solids such as fused quartz, the failure mechanism under cyclic loading is very different when compared to metals where this failure is attributable to dislocation movement and eventual slip band activity. Standard mechanical fatigue prediction methodologies, S-N or ε-N based, which have been historically developed for metals are rendered inapplicable for this class of material. The fatigue strength of Fused Silica or Fused Quartz (SiO2) material is known to be highly dependent on the stressed area and the surface finish. Stable crack growth in Region II of the V-K curve (Crack growth rate vs Stress intensity factor) is dependent on the competing and transitional effects of temperature and humidity, along that specific section of the stress intensity factor abscissa. Fused glass (under harsh environment conditions) finds usage in Automotive, Marine and Aerospace applications, where stress and load (both static and cyclic) can be severe.

The three parameter Ramberg-Osgood (RO) method finds popular usage for extracting complete stress-strain curve from limited data which is usually available. The currently popular practice of assuming the plasticity to set in only at the Yield point provides computational advantage by separating the complete nonlinear curve, obtained from RO method, into elastic and plastic regions. It is shown, with an example problem, that serious errors are committed by using this method if one compares the obtained results with results of complete stress-strain curve. In the present work we propose a simple Taylor series based approach based on RO method to overcome the above deficiency. This method is found to be computationally efficient. The proposed method is applicable for stress-strain curves of materials for which RO method provides a good approximation.

Global vehicle emissions reduction initiatives have warranted the development and usage of new materials and processes not traditionally used in the automotive industry besides exclusive applications. To support this mandate, vehicle lightweighting via metal replacement and design optimization has come into sharp focus as a doubly rewarding effect; namely, a lighter vehicle system not only requires less road load power for motivation, but also allows for smaller, usually more efficient powertrain options, which tend to be more efficient still. The automotive industry has begun to embrace adapting composite materials that have typically been available only to the upper end of the market and specialty racing applications. The specific component detailed in this paper highlights the challenges and rewards for metal replacement with an injection molded, fiber reinforced plastic for usage in mass produced drivetrain systems, namely the Electronic Limited Slip Differential (eLSD).