Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics

The flow created by the shape of a vehicle and by environmental conditions, such as cross-winds, will influence the dynamics of a vehicle. The objective of this paper is to correlate the driver’s subjective judgement of drivability with quantities which are measurable during a vehicle test...

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Main Authors: Arun Kumar, Simone Sebben, Erik Sällström, Bengt J.H. Jacobson, Alexander Broniewicz
Format: Article
Language:English
Published: MDPI AG 2019-07-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/12/14/2839
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author Arun Kumar
Simone Sebben
Erik Sällström
Bengt J.H. Jacobson
Alexander Broniewicz
author_facet Arun Kumar
Simone Sebben
Erik Sällström
Bengt J.H. Jacobson
Alexander Broniewicz
author_sort Arun Kumar
collection DOAJ
description The flow created by the shape of a vehicle and by environmental conditions, such as cross-winds, will influence the dynamics of a vehicle. The objective of this paper is to correlate the driver’s subjective judgement of drivability with quantities which are measurable during a vehicle test. For this purpose, a sedan vehicle, fitted with different aerodynamic external devices that create disturbances in the flow field, were assessed on a test track. These configurations intend to result in substandard straight line drivability. The aerodynamic devices investigated are an inverted wing, an inverted wing with an asymmetric flat plate and an asymmetric air curtain attached under the bumper. The devices generate more lift and asymmetric forces resulting in increased vehicle sensitivity to external disturbances. Pairs of configurations with and without bumper side-kicks are also tested. The side-kicks create a defined flow separation which helps to stabilize the flow and increase drivability. Plots of mean and standard deviation and ride diagram of lateral acceleration, yaw velocity, steering angle and steering torque are used to understand vehicle behaviour for the different configurations. Ride diagrams are used to visualize vehicle excitations with transient events separated from the stationary signal. The range of the measured quantities for understanding the drivability is not predicted in advance and it turns out that the error margins of the measurements are smaller than the measurement uncertainty of the Inertia Measurement Unit. Although the outcome lacks the ability to objectively quantify subjective judgements, it provides a useful qualitative assessment of the problem as the trends agree well with the subjective judgement of the driver.
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spelling doaj.art-195dda3d307e4ddc8780b0aaacf350b72022-12-22T02:54:15ZengMDPI AGEnergies1996-10732019-07-011214283910.3390/en12142839en12142839Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to AerodynamicsArun Kumar0Simone Sebben1Erik Sällström2Bengt J.H. Jacobson3Alexander Broniewicz4Department of Mechanics and Martime Sciences, Chalmers University of Technology, Hörsalsvägen 7A, SE-412 58 Göteborg, SwedenDepartment of Mechanics and Martime Sciences, Chalmers University of Technology, Hörsalsvägen 7A, SE-412 58 Göteborg, SwedenVolvo Car Corporation, Torslanda, SE-405 31 Göteborg, SwedenDepartment of Mechanics and Martime Sciences, Chalmers University of Technology, Hörsalsvägen 7A, SE-412 58 Göteborg, SwedenVolvo Car Corporation, Torslanda, SE-405 31 Göteborg, SwedenThe flow created by the shape of a vehicle and by environmental conditions, such as cross-winds, will influence the dynamics of a vehicle. The objective of this paper is to correlate the driver’s subjective judgement of drivability with quantities which are measurable during a vehicle test. For this purpose, a sedan vehicle, fitted with different aerodynamic external devices that create disturbances in the flow field, were assessed on a test track. These configurations intend to result in substandard straight line drivability. The aerodynamic devices investigated are an inverted wing, an inverted wing with an asymmetric flat plate and an asymmetric air curtain attached under the bumper. The devices generate more lift and asymmetric forces resulting in increased vehicle sensitivity to external disturbances. Pairs of configurations with and without bumper side-kicks are also tested. The side-kicks create a defined flow separation which helps to stabilize the flow and increase drivability. Plots of mean and standard deviation and ride diagram of lateral acceleration, yaw velocity, steering angle and steering torque are used to understand vehicle behaviour for the different configurations. Ride diagrams are used to visualize vehicle excitations with transient events separated from the stationary signal. The range of the measured quantities for understanding the drivability is not predicted in advance and it turns out that the error margins of the measurements are smaller than the measurement uncertainty of the Inertia Measurement Unit. Although the outcome lacks the ability to objectively quantify subjective judgements, it provides a useful qualitative assessment of the problem as the trends agree well with the subjective judgement of the driver.https://www.mdpi.com/1996-1073/12/14/2839drivabilityride diagramdrive qualityaerodynamicsvehiclehigh speedstability
spellingShingle Arun Kumar
Simone Sebben
Erik Sällström
Bengt J.H. Jacobson
Alexander Broniewicz
Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics
Energies
drivability
ride diagram
drive quality
aerodynamics
vehicle
high speed
stability
title Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics
title_full Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics
title_fullStr Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics
title_full_unstemmed Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics
title_short Analysis of Subjective Qualitative Judgement of Passenger Vehicle High Speed Drivability due to Aerodynamics
title_sort analysis of subjective qualitative judgement of passenger vehicle high speed drivability due to aerodynamics
topic drivability
ride diagram
drive quality
aerodynamics
vehicle
high speed
stability
url https://www.mdpi.com/1996-1073/12/14/2839
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