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Technical Paper

A general framework for the experimental characterization of nonlinearities and its application to a laminated assembly of an electrical motor

2022-06-15
2022-01-0944
As the vehicle industry is in the middle of transformation, the development of electric drives came into focus of engineers. The parameter evaluation of dynamic systems can be cumbersome when having nonlinearity in the structure, for example nonlinear stiffness characteristics. In such case, the standard linear approach, including EMA (Experimental Modal Analysis), modal superposition, FRF measurement (Frequency Response Function) and modal synthesis can not be applied. However, one of the main challenges in addressing nonlinearities is the lack of general tools to approach them. In this paper, a general framework is presented aiming the examination of nonlinearities in a structural dynamic context. The method relies on standard random and sine sweep testing approaches to detect and localize nonlinearities, and on dedicated processing techniques to analyze the data and extract information on the nature of the analyzed nonlinearity.
Technical Paper

Effects of Boundary Layer and Local Volumetric Cells Refinements on Compressor Direct Noise Computation

2022-06-15
2022-01-0934
The use of turbochargers with downsized internal combustion engines improves road vehicles’ energy efficiency but introduces additional sound sources of strong acoustic annoyance on the turbocharger’s compressor side. In the present study, direct noise computation (DNC) is carried out on a passenger vehicle turbocharger compressor. The work focuses on assessing the influence of grid parameters on the acoustic predictions, to further advance the maturity of the acoustic modelling of such machines with complex three-dimensional features. The DES study investigates the influence of the inflation layers characteristics, and of the spatial resolution of the mesh, on the simulated acoustic signatures. In the core mesh, refinements are applied in areas of major acoustic production, to generate cells with sizes proportional to the local Taylor microscale values.
Technical Paper

Characterization and modelling of mounts for electric powertrains

2022-06-15
2022-01-0986
The topic of this paper is to deal with the filtering of medium and high frequency excitations generated by electrified powertrains. It is now recognized that the whining noise generated by the electromagnetic forces and/or the meshing process of the transmission can propagate to the car-body through the rubber mounts. In the design phase, the prediction of the structure borne contribution requires a good knowledge of the dynamic behavior of the rubber mounts. The main issue is the stiffness of the mounts which cannot be modeled as pure springs. In fact, the dynamic behavior of a mount is governed by the material rheology and its internal resonances. The work presented in this paper propose a simulation workflow for the rubber mounts dynamic model and a methodology for the dynamic stiffness measurement including the sensitivity with the preload and with the amplitude of the excitation. Finally, experimental and digital data are compared to assess the simulation method.
Technical Paper

NVH Refinement of Automotive HVAC System

2022-06-15
2022-01-0982
The present day, car performance is more prevailing option to fascinate the buyer in IC and electric passenger vehicle. Acoustic and thermal performance balancing of heating ventilation and air conditioning (HVAC) system within car cabin proves to be critical aspect for automotive OEM. The HVAC system induced noise inside car cabin could be significant discomfort to passengers. For this reason, acoustic quality is becoming increasingly prioritized as a key design issue throughout the entire development process of HVAC system. The paper studies the advancement in using innovative development tools to map the HVAC system noise performance at vehicle level and evaluating at sub component level for noise, vibration and transient flow of refrigerant fluid induced noise with the help of universal buck under controlled condition.
Technical Paper

On the different contributions of mounts and flexible hoses on the structure borne noise of refrigerant compressors

2022-06-15
2022-01-0983
Air conditioning acoustics have become of paramount importance in electric vehicles, where noise from electromechanical components is no longer masked by the presence of the internal combustion engine. The coolant compressor is one of the most important elements in the HVAC systems of a car in terms of vibration and noise generation. The generated structural noise is studied in detail in a prototype installation, and the noise transmission and propagation mechanisms are analyzed and discussed. Through ”in situ” measurements and virtual point transformation the rotor unbalance forces and torques acting within the component are identified. The dynamic properties of the rubber mounts installed between the compressor and its support are identified thanks to matrix inversion methods. To assess the quality of the proposed procedure, the synthesised sound pressure level (SPL) is compared with experimental (SPL) measurements in different operational conditions.
Technical Paper

Experimental characterization and dynamic modelling of electrical cables

2022-06-15
2022-01-0952
Electric high voltage (HV) cables are commonly used in electrified vehicles. These cables are well known for being potential flanking transmission paths for structure-borne sound in a broad frequency range and must therefore be included in the NVH design process. Although many different layouts exist automotive HV cables fundamentally exhibit a layered structure consisting of a conductive core covered by, in sequence, an isolating sheath, a wire mesh shield to minimize electromagnetic interference and an outer jacket. The conductive core consists of hundreds of thin copper or aluminum wires organized in strands which are wound in a helical pattern. An extensive measurement campaign was carried out to dynamically characterize different cable specimen in terms of multi-degree of freedom transfer impedances.
Technical Paper

ANC: A Low-cost Implementation Perspective

2022-06-15
2022-01-0967
In the present work, we describe a low-cost implementation of an Active Noise Cancellation (ANC) system. The most interesting feature of our implementation is the use of general-purpose hardware, without the need of expensive and hard-to-program Digital Signal Processing (DSP) devices. In particular, the reference signals, collected with accelerometers properly placed on noise-generating parts and the error feedback signals are collected by means of an USB interface. All signal processing, aimed at primary path estimation and anti-noise audio signal generation, is performed using Simulink running on a commercial mini PC. The Exponential Sine Sweep (ESS) method is adopted for the measurement of the secondary path from the cancellation loudspeakers to the error microphones. An adaptive Filtered-X Least Mean Square (LMS) algorithm determines the anti-noise audio signal to be emitted.
Technical Paper

Mixture Formation Analysis for Diesel, n-Dodecane, RME, and HVO in Large-Scale Injector Nozzles

2022-06-14
2022-37-0019
Momentum conservation is a principle rule that affects the behaviour of vapour jet and liquid spray penetration. The air entrainment and mixture formation processes are dominated by the momentum transferred from the fuel to the ambient gas. Thus, it is a significant factor in the development of spray and jet penetration. This mixture formation process is well described for small-scale passenger car injectors; however, it has to be investigated in more detail for large-scale injector nozzles. It is the aim of this study to evaluate this process. The current work provides qualitative and quantitative results of spray and jet parameters in a constant volume combustion chamber (CVC). Two optical methods have been utilized to evaluate spray and jet details: Schlieren photography as a method to visualize the jet penetration and cone angle as well as Mie scattering for the phase change evaluation and the determination of liquid spray parameters.
Technical Paper

Model based design, prototyping and testing of a very small size electrically driven centrifugal pump

2022-06-14
2022-37-0025
Within automotive sector, there are several high-performance applications, like, for instance, those referred to racing and motorsport, where cooling needs are usually fulfilled by simple circuits with conventional low-efficiency pumps. The cooling needs in these applications are represented by low flow rates delivered and pressure ratios which depends on the permeability of the circuits. The operating conditions of these pumps are usually characterized by very high revolution speeds which intrinsically causes a low efficiency and critical intake phenomena (cavitation). The high speed of revolution requested by the reduced space available on board invites to consider an electrical actuation which avoids mechanical connections with the engine and produces very integrated and compact solutions guaranteeing interesting cooling performances useful also for more conventional engines (thermal management due to the electrical actuation of the pump).
Technical Paper

Mixture Formation Analysis for Diesel, n-Dodecane, RME, and HVO in Large-Scale Injector Nozzles

2022-06-14
2022-37-0020
Momentum conservation is a principle rule that affects the behaviour of vapour jet and liquid spray penetration. The air entrainment and mixture formation processes are dominated by the momentum transferred from the fuel to the ambient gas. Thus, it is a significant factor in the development of spray and jet penetration. This mixture formation process is well described for small-scale passenger car injectors; however, it has to be investigated in more detail for large-scale injector nozzles. It is the aim of this study to evaluate this process. The current work provides qualitative and quantitative results of spray and jet parameters in a constant volume combustion chamber (CVC). Two optical methods have been utilized to evaluate spray and jet details: Schlieren photography as a method to visualize the jet penetration and cone angle as well as Mie scattering for the phase change evaluation and the determination of liquid spray parameters.
Technical Paper

Unmanned Aerial Solution for Ecological Mapping Surveillance

2022-05-26
2022-26-0026
The proposed UAV can be used to triangulate the areas of unnatural deforestation, by processing the areas undergoing land cover transition. Thus, restraining illegal logging and deforestation and, ultimately, facilitating the ecological succession cycle. It identifies the green cover which helps in predicting the population of the feeding animal species and the biodiversity. The system will be influential for curbing the exploitation of landscapes with heterogeneous habitats and diverse topographical features. The model employs onboard automated controller - ARDUPILOT MissionPlanner, a flight controller, GPS and telemetry module. The setup collects data from the controller such as Altitude, GPS location, Pitch, Roll, etc. and transmits it to the Ground Control Station (GCS) during cruise. The mission planner is programmed by selecting the target survey area which is divided into a grid, Home which is the launch point and Waypoints which will be crossed autonomously.
Standard

Automotive Gear Lubricants for Commercial and Military Use

2022-05-20
CURRENT
J2360_202205
The gear lubricants covered by this standard exceed American Petroleum Institute (API) Service Classification API GL-5 and are intended for hypoid-type, automotive gear units, operating under conditions of high-speed/shock load and low-speed/high-torque. These lubricants may be appropriate for other gear applications where the position of the shafts relative to each other and the type of gear flank contact involve a large percentage of sliding contact. Such applications typically require extreme pressure (EP) additives to prevent the adhesion and subsequent tearing away of material from the loaded gear flanks. These lubricants are not appropriate for the lubrication of worm gears. Appendix A is a mandatory part of this standard. The information contained in Appendix A is intended for the demonstration of compliance with the requirements of this standard and for listing on the Qualified Products List (QPL) administered by the Lubricant Review Institute (LRI).
Standard

Classification System for Rubber Materials

2022-05-19
WIP
J200
This classification system tabulates the properties of vulcanized rubber materials (natural rubber, reclaimed rubber, synthetic rubbers, alone or in combination) that are intended for, but not limited to, use in rubber products for automotive applications. NOTE 1: The SAE Committee on Automotive Rubber Specifications (CARS) has the sole responsibility for SAE J200. CARS Works closely with and receives input from ASTM Subcommittee D11.30 on Classification of Rubber Compounds with the goal to keep SAE J200 and ASTM D 2000 technically equivalent. Candidate materials presented for development of new tables or for inclusion in Tables A1 or A2 of SAE J200 or Table X1.1 of ASTM D 2000 shall be initiated with the SAE CARS Committee. The procedure to be followed is detailed in Appendix C of SAE J200. NOTE 2: This document may serve many of the needs of other industries in much the same manner as SAE numbered steels.
Standard

Fusible Links

2022-05-18
WIP
J156
This standard covers supplemental requirements for low tension primary cable intended for use as Fusible Links (Fuse Links) at a nominal system voltage of 60 V DC (25 V AC) or less in surface vehicle electrical systems. These supplemental requirements are intended to qualify cables for an extreme current overload.
Standard

V-Ribbed Belts and Pulleys

2022-05-16
CURRENT
J1459_202205
This SAE Standard covers the dimensioning technique, tolerances, and methods of measurement of V-ribbed belts and mating pulleys for use on automotive accessory drives.
Standard

Cast Shot and Grit Size Specifications for Peening and Cleaning

2022-05-11
WIP
J444
This SAE Recommended Practice pertains to blast cleaning and shot peening and provides for standard cast shot and grit size numbers. For shot, this number corresponds with the opening of the nominal test sieve, in ten thousandths of inches , preceded by an S. For grit, this number corresponds with the sieve designation of the nominal test sieve with the prefix G added. These sieves are in accordance with ASTM E 11. The accompanying shot and grit classifications and size designations were formulated by representatives of shot and grit suppliers, equipment manufacturers, and automotive users.
Technical Paper

Effects of Structure and System Parameters on Fuel Leakage Characteristics of Precision Coupling Components in Fuel Injector for Modern Diesel Engine

2022-05-11
2022-01-5028
Increasing rail pressure is the development trend of high-pressure common rail system. When the rail pressure reaches ultrahigh range, fuel leakage of precision coupling components could have a significant impact on system performance. In order to investigate the effects of system and structure parameters on the leakage characteristics of precision coupling components, guide the design of ultrahigh-pressure common rail system, simulations were carried out. Variation of fuel leakage were studied with different structure and system parameters. A three-dimensional model of oil film with eccentric was developed to simulate eccentric between two parts of coupling component. The leakage in control valve component increases with common rail pressure; however, there is no obvious change in leakage of control piston component with rail pressure.
Standard

Mobile Air Conditioning System Refrigerant Emission Charts for R-134a, R-1234yf, and R-152a

2022-05-10
WIP
J2727
The “system emissions chart” contained herein is intended to serve as a means of estimating the annual refrigerant emission rate (grams per year) from new production A/C systems equipped with specified component technologies. It provides emission values for various component technologies that are currently available, and can be expanded as new technologies are commercialized. This document provides the information to develop an Excel file template “system emissions chart” for system emission analysis. The chart includes automotive compressor technologies for conventional mobile air conditioning systems, as well as those using semi-hermetic compressors. This standard can be considered a companion document to SAE J2763. SAE J2727 estimates system emissions, taking into account production assembly variation and accounts for components that are 100% helium leak tested prior to vehicle final assembly.
Standard

Seat Belt Hardware Performance Requirements

2022-05-09
WIP
J141
This SAE Recommended Practice describes performance requirements for hardware used in motor vehicle seat belt assemblies when tested in accordance with the test procedures specified in SAE J140. Test procedures and performance requirements for retractors will be covered in separate SAE Recommended Practices to be issued later.
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