SuperFlow AutoDyn, Руководство оператора

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AutoDyn
Operators Manual
Section 8 - Page 8
Theory Of Testing.fm
Every SuperFlow chassis dynamometer is calibrated for inertia of the roll, of the Eddy Current
absorber, and of the blowers where applicable. These calibrated values are stored in the
electronics of each individual system.
The same technology also allows us to measure parasitic losses (bearing losses, windage,
aerodynamic losses) of every rotating part down to the nearest 1/100 of one horsepower. Again,
each roll, absorber, and blower is calibrated and the values are stored in the electronics.
Aerodynamic losses are adjusted as a function of air density for greatest accuracy.
Acceleration is calculated from speed measurements obtained with a tooth gear and magnetic
pick-up. The roll speed measurement is referenced, filtered, and processed to result in several
acceleration calculations per revolution of the roll. This results in a much higher resolution than
any other system on the market.
The sophisticated technology used in the calibration and in the electronic circuits guarantees the
most accurate power measurements possible.
8.4 Interpreting Power Measurements
The SuperFlow chassis dynamometer displays several power calculations. The most important
are Wheel Power and Corrected Wheel Power. See the “Description of the Configuration File”
(Chapter 9.2.3) for details on the actual calculation formulas used in the system.
8.4.1 Wheel Power
Wheel power is the power that the vehicle puts to the ground in the conditions prevailing on the
day of the test. All corrected power and wheel torque numbers are derived from this measurement.
Wheel power is the power actually measured at the tire contact patch in the atmospheric
conditions of the test. It is the sum of the inertia power measurement plus the power applied by the
Eddy Current absorber plus the parasitic power losses of the dynamometer. No corrections are
applied.
This number should be the same as the uncorrected wheel power number of comparable
dynamometer systems in similar conditions, provided these systems also take the parasitic losses
in the dynamometer itself into consideration and are properly calibrated.
8.4.2 Corrected Wheel Power
Corrected wheel power is the measured wheel power corrected to standard atmospheric
conditions. This is the power that the vehicle would put to the ground when tested in standard
atmospheric conditions. The correction is only valid for full throttle tests.
A variety of power correction factors exist. They are available from the Society of Automotive
Engineers (SAE, STP), the European Community (ECE), the German Industry Standards (DIN),