Prediction of vehicle combination drag area including crosswind sensitivity
AssigneeVolvo Truck Corporation
InventorsMikael ASKERDAL, Jonas FREDRIKSSON
Life of this patent
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Abstract
A computer-implement method of predicting a drag area (as function of air-attack angle) of a vehicle combination after hypothetically changing an exterior shape of the vehicle combination from a first exterior shape to a second exterior shape is provided. The method includes obtaining a first drag area function, obtaining a first projected area function, obtaining a second projected area function, and predicting a second drag area function based on a rescaling of the first drag area function by a ratio of the second projected area function to the first projected area function.
Claims14
A computer-implemented method of predicting a drag area of a vehicle combination after hypothetically changing an exterior shape of the vehicle combination from a first exterior shape to a second exterior shape, the method comprising:
- obtaining a first drag area function ([CdA]*(θ)) indicating a dependence of a drag area of the vehicle combination having the first exterior shape on air attack angle (θ);
- obtaining a first projected area function (Ap*(θ)) indicating a dependence of a projected frontal area of the vehicle combination having the first exterior shape on air attack angle;
- obtaining a second projected area function (Ap(θ)) indicating a dependence of a projected frontal area of the vehicle combination having the second exterior shape on air attack angle;
- and
- predicting a second drag area function ([CdA](θ)) indicating a dependence of a drag area of the vehicle combination having the second exterior shape on air attack angle, based on a rescaling of the first drag area function by a ratio (Ap(θ)/Ap*(θ)) of the second projected area function to the first projected area function.
A device for predicting a drag area of a vehicle combination after hypothetically changing an exterior shape of the vehicle combination from a first exterior shape to a second exterior shape, the device comprising processing circuitry configured to cause the device to:
- obtain a first drag area function ([CdA]*(θ)) indicating a dependence of a drag area of the vehicle combination having the first exterior shape on air-attack angle (θ);
- obtain a first projected area function (Ap*(θ)) indicating a dependence of a projected frontal area of the vehicle combination having the first exterior shape on air-attack angle (θ);
- obtain a second projected area function (Ap(θ)) indicating a dependence of a projected frontal area of the vehicle combination having the second exterior shape on air-attack angle (θ), and
- predict a second drag area function ([CdA](θ)) indicating a dependence of a drag area of the vehicle combination having the second exterior shape on air-attack angle (θ), based on a rescaling of the first drag area function by a ratio (Ap(θ)/Ap*(θ)) of the second projected area function to the first projected area function.
A computer program for predicting a drag area of a vehicle combination after hypothetically changing an exterior shape of the vehicle combination from a first exterior shape to a second exterior shape, the computer program comprising computer code that, when running on processing circuitry of a device, causes the device to:
- obtain a first drag area function ([CdA]*(θ)) indicating a drag area in terms of air-attack angle (θ) for the vehicle combination having the first exterior shape;
- obtain a first projected area function (Ap*(θ)) indicating a projected frontal area in terms of air-attack angle for the vehicle combination having the first exterior shape;
- estimate a second projected area function (Ap(θ)) indicating a projected frontal area in terms of air-attack angle for the vehicle combination having the second exterior shape, and
- predict a second drag area function ([CdA](θ)) indicating a drag area in terms of air-attack angle for the vehicle combination having the second exterior shape, based on a rescaling of the first drag area function by a ratio (Ap(θ)/Ap*(θ)) of the second projected area function to the first projected area function.
Dependencies are inferred from the claim text.