The use of higher strength lightweight materials is also a contributory factor. This is known as the ‘continuity equation’ and it is true for any steady flow system regardless of changes in the cross-sectional area of the duct. Issue 2 – April 2003 Page 10-17 JAR 66 CATEGORY B1 uk engineering MODULE 15 GAS TURBINE ENGINES 10.4.7 MAGNETIC CHIP DETECTOR Magnetic detectors may be fitted into the oil system at various points to collect and hold ferrous debris. The loads on the bearings are of three main forms. (on early types) Capacity limited by tip speed. The starter/driven gearshaft (fig.8.11.) The Flow Type ACU. Main Gallery and Vaporisers The main gallery connects with delivery tubes, each feeding one vaporiser head through a distribution orifice. Thus the propelling nozzle of a re-heat engine must be able to provide a nozzle area suitable for normal running without re-heat and a larger nozzle area when re-heat is used. 5 PSI and do not require a bag. Sensors similar to these can be used for active tip clearance control, where it senses the gap between the casing and the blade. The ignition fuel flow is used with ignition plugs and catalytic ignition systems. Lift/drag Vectors for Different Angles of Attack. engineering Issue 2 – April 2003 Page 19-30 JAR 66 CATEGORY B1 uk engineering MODULE 15 GAS TURBINE ENGINES Number Item 10 Front Mount Adapter 20 Anti-Icing System 30 Vibration Transducer 40 Hydraulic Lines 50 Inlet Cowling 60 Hydraulic Hoses 70 Hydraulic Pump No. In this instance, the flame tube is of the same general shape as for atomisation, but has no swirl vanes or flare. As the vanes of the centrifugal breather rotate, the oil in the mixture is caught in the vanes and thrown back into the gearbox; the air being vented to atmosphere. It is a very undesirable condition, which can rapidly cause serious damage to the engine. This information indicates that explosive conditions in the vapour space will occur with the low volatility turbine fuel under extremely hot weather conditions and with gasoline under extremely low temperature conditions. This method is, therefore, not used. Turbine blades must also be resistant to fatigue and thermal shock, so that they will not fail under the influence of high frequency fluctuations in the gas conditions, and they must also be resistant to corrosion and oxidisation. In all modern gas turbine engines, the engine produces its own pressurized gas, and it does this by burning something like propane, natural gas… Compressor R.P.M = 8,000 Compressor R.P.M. The maximum flame temperature for hydrocarbon fuels is roughly 2,000C. Because of the small amount of oil in circulation and the high bearing temperatures, good resistance to oxidation is essential. The amplitude range over which the device is required to perform. At ground level the comparative temperature limits of flammability for gasoline and kerosene is as follows: a) Gasoline. Issue 2 – April 2003 Page 20-7 JAR 66 CATEGORY B1 uk engineering MODULE 15 GAS TURBINE ENGINES 20.3 FIRE AND LOOP FAULT INDICATION (E.C.A.M.) This allows fuel flow through to the secondary nozzle as well as the primary nozzle. s. Figure 21.25. Issue 2 – April 2003 Page 9-12 JAR 66 CATEGORY B1 uk engineering MODULE 15 GAS TURBINE ENGINES 9.6.4 SAFETY PRECAUTIONS There is much less risk of fire with oil, however it will burn if the conditions are right. Because less power will be required to drive the compressor, the fuel control system reduces the fuel flow to maintain a constant engine rotational speed or turbine entry temperature, as appropriate; however, because of the decrease in air density, the thrust will be lower. LP Fuel Filter. Thus, for a given volume of fuel, kerosene gives an increased aircraft range when compared with gasoline, but weighs more. If this steady pressure increase breaks down, efficient film lubrication ceases and boundary lubrication occurs. When the compressor is operating at speeds below its designed rpm range, the axial velocity of the airflow through the compressor will decrease which will cause an increase in the angle of attack of the compressor blades. static and dynamic pressure). The E.C.A.M. The computer varies the rates of fuel flow to the engines to suit the changing power demands occasioned by alterations of rotor blade pitch. (a computer that senses pitot pressure, static pressure and total air temperature) e. Engine RPMs – N1 and N2. Computer Signalling. Issue 2 – April 2003 Page 2-8 JAR 66 CATEGORY B1 uk engineering MODULE 15 GAS TURBINE ENGINES 2.3.1 EFFECT OF FORWARD SPEED Since reference will be made to ‘ram ratio’ and Mach number, these terms are defined as follows: Ram ratio is the ratio of the total air pressure at the engine compressor entry to the static air pressure at the air intake entry. Issue 2 – April 2003 Page 16-9 JAR 66 CATEGORY B1 uk engineering MODULE 15 GAS TURBINE ENGINES 16.8.1 CONSTANT SPEED UNIT In the normal flight range, the main control of the propeller is exercised by the propeller control unit (PCU). b) The fuel must be introduced into the combustion system in a readily combustible form and the system must be able to automatically adjust the fuel flow to match the air available in order to maintain the selected RPM under all operating conditions. Cooling of the external skin of an aero-engine is achieved by suitable design of the aircraft airframe; the layout will depend upon where the engine is fitted and what kind of engine compartment is used. (4) TEMPERATURE RANGE. Each pump returns the oil from a particular part of the engine and is protected by a coarse filter (or strainer) in the return line. Efforts are made to design engine bearing housings and carcasses with suitable stiffness to avoid resonance in the engine running range. However, the basic principles remain the same and can be explained by using an example. Nozzle Guide Vane Cooling Air. Effects of Air Temperature and Altitude on Thrust.