Accession Number : AD0859552

Title :   Operating Characteristics of Turbojet Engines with Afterburners,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH

Personal Author(s) : Rzewski, Henryk ; Bekiesinski, Ryszard

Report Date : 27 JUN 1969

Pagination or Media Count : 12

Abstract : With high-altitude, low-speed flight, pressures in certain types of afterburner chambers may be so low as to prevent ignition and stable fuel combustion; the larger the exhaust-nozzle exit cross-section area of the afterburner, the lower the pressure in the afterburner chamber, and the more difficult fuel ignition. Therefore, during afterburner startup, engine-control instruments, especially the gas-temperature indicator behind the turbine must be watched carefully, and the afterburner startup must be stopped when it exceeds the permitted maximum value. Emergency shotoff switches serve this purpose. In some aircraft types, the afterburner exhaust-nozzle exit area is not reduced automatically. If the exhaust-nozzle fails to close, aircraft flight and tactical characteristics deteriorate considerably. Since nominal and maximum rpm's are equal in modern engines, their thrust is increased by increasing gas temperature before the turbine and by changing the exhaust-nozzle exit cross-section area; it is recommended that such engines be run for 10 to 15 sec at maximum rate before starting the afterburner; thus the afterburner chamber is heated up and starting conditions are improved. (Author)

Descriptors :   (*TURBOJET ENGINES, OPERATION), (*AFTERBURNERS, TURBOJET ENGINES), HIGH ALTITUDE, PRESSURE, EXHAUST NOZZLES, AIRCRAFT ENGINES, NOZZLE AREA RATIO, STARTING, POLAND.

Subject Categories : Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE