Vendetta Final Proposal Part 1 (3.4 MB) - Cal Poly

6 PropulsionIn developing the propulsion system for the Vendetta, the RFP specifications of supersonic cruise and stealth arethe driving factors. Due to the frontal RCS requirement, the fan blades of the engine must remain hidden which drivesthe engine placement well inside the aircraft.6.1 Engine SelectionThe RFP specifies a Low-Bypass-Ratio Turbofan (LBR-TF) or a Turbojet (TJ) engine may be used to perform themission. Both sizing equations and a candidate engine deck, an axisymmetric center body inlet and a mixed flow ejectornozzle, were supplied with the RFP, with an option to use either or neither. Since it included physical dimensions andfuel flow values the RFP engine deck was used instead of the equations provided by the RFP. The RFP enginespecifications are shown in Table 6.I.Table 6.I - Engine Specifications of RFP Supplied EngineEngine and Nozzle LengthPropulsion System LengthFan Face DiameterMaximum DiameterWeight with Nozzle310 in425 in50 in65 in7200 lbThe engine supplied by the RFP includes fuel flow and thrust data for part power, idle power, and military power.All engine data supplied by the RFP are corrected to sea level and a Mach number of zero. Therefore, every value forthrust and fuel flow at each altitude and Mach number is given in corrected net propulsive force (NPF c ) and correctedfuel flow (W Fc ). To find the actual thrust (NPF) and fuel flow (W F ) the following equations were used:NPF = NPF ⋅ dcT0.6F=F⋅c T⋅TW W Q ddT= +MPP2 3.5(1 .2 ) ( )SLT2QT= 1+0.2 M ( ) TSLOnce the data were uncorrected the military thrust was found. The RFP supplied equations that could be used to scale theengine based on a desired thrust. The scaling equations are as follows:26