SuperFlow AutoDyn, Руководство оператора

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AutoDyn
Operators Manual
Section 8 - Page 10
Theory Of Testing.fm
There are power correction standards for gasoline and diesel engines, for applications in road
vehicles, stationary engines, or marine engines, etc. For a SuperFlow chassis dynamometer,
relevant standards are those generally intended for gasoline engines in road vehicles.
Power correction standards try to estimate what the vehicle power would be under reference
conditions. They cannot calculate exactly what that power output would be. The greater the
difference between the ambient conditions during the test and the reference conditions, the
greater the error in the estimate. Most correction standards include limits on their applicability. This
limit is typ/- 7%. This means if the correction factor is greater than (>) 1.07 or less than (<)
0.93, the corrected power numbers are not considered to be acceptable, and the test should be
performed again under conditions which are closer to the reference conditions.
For most applications this is less of a problem, and the corrected power numbers are still the best
basis for comparisons. However, keep this into consideration when comparing test results
obtained under considerably different test conditions. At a single location, the correction factor will
usually vary less than 5% through the year.
Power corrections are only valid for Wide Open Throttle (WOT) tests. Corrected power numbers
for any test performed under partial throttle conditions should be disregarded.
8.5.1 Standards
Several Standards organizations have determined methods for estimating power under reference
conditions. The best-known organizations are:
• SAE (Society of Automotive Engineers), USA
• ECE (European Community), Europe
• DIN (Deutsche Industrie Norm), Germany
• ISO (International Standards Organization), worldwide
• JIS (Japanese Institute for Standardization), Japan
The default configurations supplied with the SuperFlow chassis dynamometer include power
corrections to the following standards: SAE, STP, ECE, DIN.
There is a tendency for all these standards to converge. The only
worldwide power correction standards at this time are the ones
determined by ISO. For internal combustion engines in road vehicles, this
is the ISO 1585 standard. The current SAE J 1349 and ECE standards
are nearly identical to the ISO 1585 standard.
8.5.1.1 SAE
The SAE standard applied is a modified version of the SAE J1349 standard of June 1990. Power
is corrected to reference conditions of 29.23 InHg
[99 kPa] of dry air and 77 F [25 C] . This is the
default correction used on CycleDyns.
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