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A Study on the Effect of Debris Location on a Double Element Wing in Ground Effect

Loughborough University-Tom Marsh, Graham Hodgson, Andrew Garmory, Dipesh Patel
  • Technical Paper
  • 2020-01-0693
To be published on 2020-04-14 by SAE International in United States
Multi-element front wings are essential in numerous motorsport series, such as Formula 1, for the generation of downforce and control of the onset flows to other surfaces and cooling systems. Rubber tyre debris from the soft compounds used in such series can become attached to the wing, reducing downforce, increasing drag and altering the wake characteristics of the wing. This work studies, through force balance and Particle Image Velocimetry measurements, the effect a piece of debris has on an inverted double element wing in ground effect. The wing was mounted at a ride height determined to minimise separation from a fixed false-floor in the Loughborough University Large Wind Tunnel. The debris is modelled using a hard-setting putty and is located at different span and chord-wise positions around the wing. The sensitivity to location is studied and the effect on the wake analysed using PIV measurements. The largest effect on downforce was observed when the debris was located on the underside of the wing towards the endplates. The wake was most effected when the debris was…
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Parametric Study of Reduced Span Side Tapering on a Simplified Model with Wheels

Loughborough University-Max Varney, Martin Passmore, Ryan Swakeen
Jaguar Land Rover-Adrian Gaylard
  • Technical Paper
  • 2020-01-0680
To be published on 2020-04-14 by SAE International in United States
Sports Utility Vehicles (SUVs) often have blunt rear end geometries for design aesthetics and practicality, however, such vehicles are potentially high drag. The application of tapering; typically applied to an entire edge of the base of the geometry is widely reported as a means of reducing drag, but in many cases this is not practical on real vehicles. In this study side tapers are applied to only part of the side edge of a simplified automotive geometry, to show the effects of practical implementations of tapers. The paper reports on a parametric study undertaken in Loughborough University’s Large Wind Tunnel with the ¼ scale Windsor model equipped with wheels. The aerodynamic effect of implementing partial side edge tapers is assessed from a full height taper to a 25% taper in both an upper and lower body configuration. These were investigated using force and moment coefficients, pressure measurements and planar particle image velocimetry (PIV). These geometries showed that the drag reductions are maximised with a 50% span, generating a vertically symmetric wake and less taper drag…
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Investigation of wave stripping models on a generic wing-mirror using a Coupled Level-set Volume of Fluid simulation

Loughborough University-Maciej Skarysz, Andrew Garmory
Dassault Systemes-Jose Escobar, Jonathan Jilesen
  • Technical Paper
  • 2020-01-0682
To be published on 2020-04-14 by SAE International in United States
Predicting Exterior Water Management is important for developing vehicles that meet customer expectations in adverse weather. Fluid film methods, with Lagrangian tracking, can provide spray and surface water simulations for complex vehicle geometries in on-road conditions. To cope with this complexity and provide practical engineering simulations, such methods rely on empirical sub-models to predict phenomena such as the film stripping from the surface. Experimental data to develop and validate such models is difficult to obtain therefore here a high-fidelity Coupled Level-set Volume of Fluid (CLSVOF) simulation is carried out. CLSVOF resolves the interface of the liquid in three dimensions; allowing direct simulation of film behaviour and interaction with the surrounding air. This is used to simulate a simplified wing-mirror, with air flow, on which water is introduced. The film shows very different behaviour on the in-board section, where a film is developed which eventually breaks to rivulets, and the end of the mirror, where the water is rapidly stripped off the surface due to the higher shear stress from the air. The same case is…
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Deep optimization of catalyst layer composition via data-driven machine learning approach

Biao Xie, Wen Gu
Loughborough University-Jin Xuan, Dezong Zhao
  • Technical Paper
  • 2020-01-0859
To be published on 2020-04-14 by SAE International in United States
Proton exchange membrane fuel cell (PEMFC) is considered as a promising automotive powertrain by many governments and auto factories. However, the commercialization of PEMFCs is still limited by its high cost and insufficient lifetime at present. Catalyst layers (CLs) are the electrochemical reaction region of PEMFCs which cause a large proportion of the total cost, and the composition proportion of CLs significantly influences output performance of PEMFCs. However, traditional experimental and numerical methods cause the large economic and time cost and infeasibility in the CL composition proportion optimization. In this study, we propose a data-driven surrogate modeling framework to achieve the CL composition proportion optimization. A few simulation results provided by a three-dimensional full cell physical model as dataset to construct the representation between the CL composition proportion and output performance via data-driven approach. Genetic algorithm is employed to search the optimum CL composition proportion to obtain the maximum output performance.
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Numerical investigation of heat retention and warm-up with thermal encapsulation of powertrain

Loughborough University-Ruoyang Yuan, Kambiz Ebrahimi
Jaguar Land Rover, Ltd.-Christopher Price, Roshan Kasurkar, Mark Spenley, Nilabza Dutta
  • Technical Paper
  • 2020-01-0158
To be published on 2020-04-14 by SAE International in United States
Powertrain thermal encapsulation has the potential to improve fuel consumption and CO2 via heat retention. Heat retained within the powertrain after a period of engine-off, can increase the temperature of the next engine start hours after key-off. This in turn reduces inefficiencies associated with sub-optimal temperatures such as friction. The Ambient Temperature Correction Test was adopted in the current work which contains two World-wide harmonised Light duty Test Procedure (WLTP) cycles separated by a 9-hour soak period. A coupled 1D – 3D computational approach was used to capture heat retention characteristics and subsequent warm-up effects. A 1-D powertrain warm-up model was developed in GT-Suite to capture the thermal warm-up characteristics of the powertrain. The model included a temperature dependent friction model, the themal-hydraulic characteristics of the cooling and lubrication circuits as well as parasitic losses associated with pumps. A 23°C WLTP cycle was run via the 1D model, key fluids and solids temperatures around the engine bay calculated at the end of the 1st WLTP cycle were then imported into a 3D heat retention model,…
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Streamlined Tails – The Effects of Truncation on Aerodynamic Drag

Loughborough University-Jeff Howell, Eleanor Rajaratnam, Martin Passmore
  • Technical Paper
  • 2020-01-0673
To be published on 2020-04-14 by SAE International in United States
Significant aerodynamic drag reduction is obtained on a bluff body by tapering the rear body. In the 1930’s it was found that a practical low drag car body could be achieved by cutting off the tail of a streamlined shape. The rear end of a car with a truncated tail is commonly referred to as a Kamm back. It has often been interpreted as implying that the drag of this type of body is almost the same as that for a fully streamlined shape. From a review of the limited research into truncated streamlined tails it is shown in this paper that, while true for some near axisymmetric bodies, it is not the case for many more car-like shapes. For these shapes the drag reduction from an elongated tail varies almost linearly with the reduction in cross section area. A CFD simulation to determine the drag reduction from a truncated streamlined tail of variable length on the simple Windsor Body is shown by way of confirmation.
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Probabilistic Analysis of Bimodal State Distributions in SCR Aftertreatment Systems

Loughborough University-Rhys Comissiong, Thomas Steffen
Caterpillar-Leo Shead
  • Technical Paper
  • 2020-01-0355
To be published on 2020-04-14 by SAE International in United States
Sensor selection for the control of modern powertrains is a recognised technical challenge. The key question is which set of sensors is best suited for an effective control strategy? This paper addresses the question through probability modelling and Bayesian analysis. By quantifying uncertainties in the model, the propagation of sensor information throughout the model can be observed. The specific example is an abstract model of the slip behaviour of Selective Catalytic Reduction (SCR) DeNOx aftertreatment systems. Due to the ambiguity of the sensor reading, linearization-based approaches including the Extended Kalman Filter, or the Unscented Kalman Filter are not successful in resolving this problem. The stochastic literature suggests approximating these nonlinear distributions using methods such as Markov Chain Monte Carlo (MCMC), which is able in principle to resolve bimodal or multimodal results. However, the most effective methods are Hamiltonian solvers, which again struggle with the strongly nonlinear system behaviour, often getting stuck in just one of the possible solutions. This paper proposes a solution that uses hierarchical stochastic modelling to add another dimension to the parameter…
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Experimental Interpretation of Compression Ignition Engine In-Cylinder Flow Structures

Loughborough University-Tristan Knight, Edward Long, Ruoyang Yuan, Colin Garner, Graham Hargrave
  • Technical Paper
  • 2020-01-0791
To be published on 2020-04-14 by SAE International in United States
Understanding and predicting the possible in-cylinder flow structures that occur within compression-ignition engines is vital if further optimisation of combustion systems is to be achieved. To enable this prediction, fully validated computational models of the complex turbulent flow-fields generated during the intake and compression process are needed. However, generating, analysing and interpreting experimental data to achieve this validation remains a complex challenge due to the variability that occurs from cycle to cycle. The flow-velocity data gathered in this study, obtained from a single-cylinder CI engine with optical access using high-speed PIV, demonstrates that significantly different structures are generated over different cycles, resulting in the mean flow failing to adequately reflect the typical flow produced in-cylinder. Additionally, this high level of variability is shown by the work to impact the assessment of turbulence throughout the cycle, influencing the values often used to validate mathematical models. The work in this paper analyses experimental PIV data from the single cylinder engine, to characterise the differences between individual cycles’ bulk flow structures and the resultant turbulent fields. The analysis…
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Co-Simulation Methods for Holistic Vehicle Design: A Comparison

Loughborough University-Nikolaos Kalantzis, Tom Fletcher, Ahmed Ahmedov, Ruoyang Yuan, Antonios Pezouvanis, Kambiz Ebrahimi
AVL UK Ltd.-Richard Osborne
  • Technical Paper
  • 2020-01-1017
To be published on 2020-04-14 by SAE International in United States
Vehicle development involves the design and combination of subsystems of different domains to meet performance, efficiency, and emissions targets set during the initial developmental stages. Before a physical prototype of a vehicle or vehicle powertrain is tested, engineers build and test virtual prototypes of the design(s) on multiple stages across the development cycle. In addition, controllers and physical prototypes of subsystems are tested under simulated signals before a physical prototype of the vehicle is available. Different departments within an automotive company tend to use different modelling and simulation tools specific to the needs of a specific engineering discipline. While this makes sense considering the development of the said system, subsystem, or component, modern holistic vehicle design requires the constituent parts to operate in synergy with one-another in order to ensure system-level optimal performance. Due to the above, the integrated simulation of the models developed in different environments is necessary. This paper reviews the current trends of model integration within the automotive industry. The reviewed model integration methods are evaluated and compared with one another with…
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Holistic Thermal Energy Modelling For Full Hybrid Electric Vehicles (HEVs)

Loughborough University-Tom Fletcher, Nikolaos Kalantzis, Ahmed Ahmedov, Ruoyang Yuan, Kambiz Ebrahimi
Jaguar Land Rover-Nilabza Dutta, Christopher Price
  • Technical Paper
  • 2020-01-0151
To be published on 2020-04-14 by SAE International in United States
Full Hybrid Electric Vehicles (HEVs) are usually defined by their capability to drive in a fully electric mode, offering the advantage that they do not produce any emissions at the point of use. This is particularly important in built up areas, where localised emissions in the form of Nitrogen Oxides (NOx) and Particulate Matter (PM), may worsen health issues such as respiratory disease. However, high degrees of electrification also mean that waste heat from the Internal Combustion Engine (ICE) is often not available for heating the cabin and maintaining the temperature of the powertrain and emissions control system. If not managed properly, this can result in increased fuel consumption, exhaust emissions, and reduced electric-only range at moderately high or low ambient temperatures negating many of the benefits of the electrification. This paper describes the development of a holistic, modular vehicle model designed for development of an Integrated Thermal Energy Management Strategy (ITEMS). The developed model utilises advanced simulation techniques, such as co-simulation and surrogate modelling, to incorporate a high fidelity thermo-fluid model, a multi-phase Heating…