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Training / Education

Introduction to Power Electronics in Automotive Applications

2019-11-04
Modern power electronics (PE) devices and circuits are now in widespread use in automotive and non-automotive applications. The purpose of this course is to give an overall introduction to the key aspects of power electronic circuits, components and design in automotive applications. Topics covered include power semiconductor devices, their characteristics and operation, and their use in power electronics circuits.
Technical Paper

Feasibility of Multiple Piston Motion Control Approaches in a Free Piston Engine Generator

2019-10-22
2019-01-2599
The control and design optimization of a Free Piston Engine Generator (FPEG) has been found to be difficult as each independent variable changes the piston dynamics with respect to time. These dynamics, in turn, alter the generator and engine response to other governing variables. As a result, the FPEG system requires an energy balance control algorithm such that the cumulative energy delivered by the engine is equal to the cumulative energy taken by the generator for stable operation. The main objective of this control algorithm is to match the power generated by the engine to the power demanded by the generator. In a conventional crankshaft engine, this energy balance control is similar to the use of a governor and a flywheel to control the rotational speed. In general, if the generator consumes more energy in a cycle than the engine provides, the system moves towards a stall.
Technical Paper

Assessment of Numerical Cold Flow Testing of Gas Turbine Combustor through an Integrated Approach Using Rapid Prototyping and Water Tunnel

2019-10-11
2019-28-0051
In the present work, it is aimed at developing an integrated approach for combustor modeling involving rapid prototyping and water tunnel testing to assess the cold flow numerical simulations; the physical model will be subjected to cold flow visualization and parametric studies and CFD analysis to demonstrate its capability for undergoing rigorous cold flow testing. A straight through annular combustors is chosen for the present study because of it has low pressure drop, less weight and used widely in modern day aviation engines. Numerical Analysis has been performed using ANSYS-FLUENT. Three dimensional RANS equations are solved using k-ɛ model for the Reynolds numbers ranging from 0.64 x 105-1.5 x 105 based on the annulus diameter. Post processing the results is done in terms of jet penetration, formation of recirculation zone, effective mixing, flow split and pressure drop for different cases.
Technical Paper

Parameter Optimization during Minimum Quantity Lubrication Turning of Inconel 625 Alloy with CUO, Al2O3 and CNT Nanoparticles Dispersed Vegetable-Oil-Based Cutting Fluid

2019-10-11
2019-28-0061
Inconel 625, nickel based alloy, is found in gas turbine blades, seals, rings, shafts, and turbine disks. On the other hand, the manufacturing of this alloy is challenging, mainly when machining processes are used due to excellent mechanical properties. Application of nanofluids in minimum quantity lubrication (MQL) shows gaining importance in the machining process, which is economical and eco-friendly. The principal objective of this investigational work is to study the influence of three types of nanofluids in the MQL turning of Inconel 625 nickel based alloys. The used nanofluids are multi-walled carbon nanotubes (CNT), alumina (Al2O3) and copper oxide (CUO) dispersed in vegetable oil. Taguchi-based L27 orthogonal array is used for the experimental design. The parameter optimization of design variables over response is carried out by the use of Taguchi-based derringer's desirability function.
Technical Paper

CFD Simulation on Turbulent Forced Convection of Copper Oxide (CuO) -Water Nanofluids in a Horizontal Circular Pipe

2019-10-11
2019-28-0131
The present study provides a detailed investigation on simulation of Copper oxide nanofluids in a simple horizontal circular pipe considering turbulent forced convection, with a constant heat flux boundary condition. The simulation is carried out using three different models available in fluent viz. Newtonian single phase model, Eulerian-mixture and Eulerian-Eulerian multiphase models. The Reynold number of the flow is varied along with volume concentration of nanoparticles varying form low to high. Nanofluids rheology is studied by considering standard k-ε two equation turbulence model with enhanced wall treatment considering appropriate wall y+ values. The effective temperature dependent thermo-physical properties for nanofluids were seized from the literatures. The results from the simulation clearly showed an increase in the heat transfer characteristics with the addition of nanoparticles compared to that of base fluid alone.
Standard

Fundamentals in Wire Selection and Sizing for Aerospace Applications

2019-10-10
WIP
AIR6540A

The scope of this report is to capture fundamental principles of selecting a wire size for an aerospace application using the method prescribed in the AS50881 standard and additional calculations, not found in AS50881, to ensure the wire selection will adequately perform in the specific physical and environment conditions.

This report covers wire selection and sizing as part of the electrical wire interconnection systems (EWIS) used in aerospace vehicles. Aerospace vehicles include manned and unmanned airplanes, helicopters, lighter-than-air vehicles, missiles, and external pods. This document does not apply to wiring inside of airborne electronic equipment but shall apply to wiring externally attached to such equipment.

Journal Article

A Contribution to Improving the Thermal Management of Powertrain Systems

2019-10-08
Abstract This work presents a generalized methodology for the optimal thermal management of different powertrain devices. The methodology is based on the adoption of an electrically driven pump and on the development of a specifically designed controller algorithm. This is achieved following a Model Predictive Control approach and requires a generalized lumped-parameters model of the thermal exchange between the device walls and the coolant. The methodology is validated at a test rig, with reference to a four-cylinder spark-ignition engine. Results show that the proposed approach allows a reduction in fuel consumption of about 2-3% during the engine warm-up, a decrease in fuel consumption of about 1-2% during fully warmed operation, and an estimated fuel consumption reduction of about 2.5-3% in an NEDC. Finally, the investigation highlights that the proposed approach reduces the risk of after-boiling when the engine is rapidly switched off after a prolonged high-load operation.
Journal Article

ERRATUM

2019-10-07
The paper was originally published with the authors in the incorrect order. The correct author order should be as follows: Charlotte Fossier, Université de Lyon Dennis Barday, Volvo Group Christophe Changenet, Université de Lyon Fabrice Ville, Université de Lyon Vincent Berier, Volvo Group
Technical Paper

How to Improve SI Engine Performances by Means of Supercritical Water Injection

2019-10-07
2019-24-0235
The efficiency of ICEs is strongly affected by exhaust gases and engine cooling system heat losses, which account for about 50% of the heat released by combustion. A promising approach is to transfer this exhaust heat to a fluid, like water, and inject it into the combustion chamber under supercritical conditions. In such a way, the recovered energy is partially converted into mechanical work, improving both engine efficiency and performance. A quasi-dimensional model has been implemented to simulate an SI engine with supercritical water injection. Specifically, a spark ignition ICE, four-stroke with Port Fuel Injection (PFI) has been considered. The model accounts for gas species properties, includes valves opening/closing, wall heat transfer, a water injection model and a combustion model. The influence of some injection parameters, i.e.
Technical Paper

A Coupled Lattice Boltzmann-Finite Volume Method for the Thermal Transient Analysis of an Air-Cooled Li-Ion Battery Module for Electric Vehicles with Porous Media Insert Modeled at REV Scales

2019-10-07
2019-24-0242
Lithium ion batteries are the most promising candidates for electric and hybrid electric vehicles, owe to their ability to store higher electrical energy. As a matter of fact, in automotive applications, these batteries undergo frequent and fast charge and discharge processes, which are associated to internal heat generation, which in turns causes temperature increase. Thermal management is therefore crucial to keep temperature in an appropriate level for safe operation and battery wear prevention. In a recent work authors have already demonstrated the capabilities of a coupled lattice Boltzmann-Finite Volume Method to deal with thermal transient of a three-dimensional air-cooled Li-ion battery at different discharging rates and Reynolds numbers. Here, in order to improve discharge thermal capabilities and reduce temperature levels of the battery itself, a layer of porous medium is placed in contact with the battery so to replace a continuum solid aluminum layer.
Technical Paper

Assessment of Energy Consumption and Range in Electric Vehicles with High Efficiency HVAC Systems Based on the Tesla Expander

2019-10-07
2019-24-0244
Battery electric vehicles (BEVs) are considered one of the most promising solution to improve the sustainability of the transportation sector aiming at a progressive reduction of the dependence on fossil fuels and the associated local pollutants and CO2 emissions. Presently, the major technological obstacle to a large scale diffusion of BEVs, is the fairly low range, typically less than 300 km, as compared to classical gasoline and diesel engines. This limit becomes even more critical if the electric vehicle is operated in severe weather conditions, due to the additional energy consumption required by the cabin heating, ventilating, and air-conditioning (HVAC). The adoption of vapor-compression cycle, either in heat pump or refrigerator configuration, represents the state-of-the-art technology for HVAC systems in vehicles. Such devices typically employ an expansion valve to abruptly reduce the pressure causing the flash evaporation of the working fluid.
Technical Paper

Combined Optimization of Energy and Battery Thermal Management Control for a Plug-in HEV

2019-10-07
2019-24-0249
This paper presents an optimization algorithm, based on discrete dynamic programming, that aims to find the optimal control inputs both for energy and thermal management control strategies of a Plug-in Hybrid Electric Vehicle, in order to minimize the energy consumption over a given driving mission. The chosen vehicle has a complex P1-P4 architecture, with two electrical machines on the front axle and an additional one directly coupled with the engine, on the rear axle. In the first section, the algorithm structure is presented, including the cost-function definition, the disturbances, the state variables and the control variables chosen for the optimal control problem formulation. The second section reports the simplified quasi-static analytical model of the powertrain, which has been used for backward optimization. For this purpose, only the vehicle longitudinal dynamics have been considered.
Standard

Cost Versus Benefits of Engine Monitoring Systems

2019-10-01
WIP
AIR4176B
The purpose of this SAE Aerospace Information Report (AIR) is to provide information that would be useful to potential users/operators and decision makers for evaluating and quantifying the benefits of an Engine Monitoring Systems (EMS) versus its cost of implementation. This document presents excerpts from reports developed to analyze "actual aircraft cost/benefits results". These are presented as follows: a. First, to outline the benefits and cost elements pertaining to EMS that may be used in performing a cost versus benefits analysis. b. Second, to present considerations for use in conducting the analysis. c. Third, to provide examples of analyses and results as they relate to the user/operator and decision-maker community. The document encompasses helicopters and fixed wing aircraft and distinguishes between civilian and military considerations.
Standard

Heater and Accessories, Aircraft Internal Combustion Heat Exchanger Type

2019-10-01
CURRENT
AS8040C
This SAE Aerospace Standard (AS) covers combustion heaters and accessories used in, but not limited to, the following applications: a. Cabin heating (all occupied regions and windshield heating) b. Wing and empennage anti-icing c. Engine and accessory heating (when heater is installed as part of the aircraft) d. Aircraft deicing
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