This SAE Aerospace Information Report (AIR) presents a discussion of drag torques of engine accessories operating at cold temperature. Various conditions of temperature, speed, and acceleration rates are reviewed showing the merits of each method and recommending a standard test method.
A general discussion is presented herein, to outline the starter functions which are necessary for a successful engine start. In addition, sample calculations are included to illustrate an accepted method of determining the engine starting time from known data. Further consideration is then given to the relationship between starter torque output and engine pad strength and a generalized formula is presented for calculating the theoretical transient torque peaks for a simplified starter-engine system. Sample calculations for actual tests are included, and the results of these calculations are compared with measured values.
This information report includes procedures for determining and presenting in standard form and terminology turbine engine starting and motoring characteristics. It further includes the requirement for substantiating the accuracy of the information presented.
This information report includes procedures for determining and presenting in standard form and terminology turbine engine starting and motoring characteristics. It further includes the requirement for substantiating the accuracy of the information presented.
The material contained in this report has been simplified to facilitate its use. Specific manufacturers should be contacted for more detailed information. Many of the basic power supplies are available in numerous configurations and some provide shaft power or electrical power in addition to the pneumatic capability. Vehicles for the ground transportation of the power supplies are also varied to fit specific requirements.