SAWE Report - Cal Poly San Luis Obispo

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14.2 Vehicle Management System The vehicle management system (VMS) of the aircraft provides flight and propulsion control and includes the following systems: Control stick, Throttle controls, Rudder pedals, and actuators, Air data probes, Accelerometers Leading-edge, flap drive actuators, Primary flight control actuators . The choice of primary actuator type was the first trade examined. Four choices are commonly available for these systems: 1) Electrohydrostatic 2) Electric 3) Pneumatic 4) Hydraulic Pneumatic systems were eliminated due to low power to weight, large comparative size, and low power transmission efficiencies. Electrohydrostatic actuators, although offering many benefits such as a “line replaceable unit”, optimized per service dynamic impedance shaping, and optimized K factor suffered from low observability and weight problems as a consequence of electric power transmission throughout the aircraft( EM emissions in the IR (actuator heating) and Radio (cables) spectra). This low observability problem to an even greater degree affected the all electric system which utilizes a comparatively large and heavy actuator. Thus the decision was made to utilize an all hydraulic system with digital fly-by-wire control. The F-119 utilized in the F-22 has a PTO driving two 72 gpm (273 lpm) pumps (main line), four pumps total to supply two independent 4000 psi (27.6 GPa) systems. The choice of the high pressure systems was due to weight and volume considerations. Peak hydraulic system demand will be satisfied via an air pressurized hydraulic reservoir allowing for a constant energy bleed from the engines. Further detail was then examined into the electric system of the aircraft. Borrowing the electrical system from the F-22, a Smiths Industries 270 volt, direct current (DC) electrical system was chosen. It uses two PTO driven 65 kilowatt generators. Next level design trade studies need to be completed on the redundancy level of the electrical and flight control systems. Flight control system design should be aimed at Operation- Operational-Operational Fail (OOOF) or better, safety design. INS/GPS and other navigational systems should be examined and a proper redundancy level chosen. 91
14.3 Fuel System Initial fuel system design began with configuration placement of fuel tanks symmetrically about the CG laterally and longitudinally. The two fuselage tanks (Figure 14.2) serve to trim the aircraft in flight, necessary for the shift in neutral point location due to supersonic flight. Aircraft sizing began with fuel load internal volume necessary to complete the mission. The final configuration provides for Figure 14.2 - Fuel Tank Locations in Vendetta 68,000 lb (30,770 kg) of fuel to be carried within 80 %(fuselage) and 75 %(wings) volume usage tanks. All tanks in the aircraft are pressurized with nitrogen gas from the on-board inert gas generating system (OBIGGS). Pressurizing is minimal due to structural constraints and JP-8’s low vapor pressure of 0.029 psia @ 100 °F (200 Pa @ 42.3 °C). Nitrogen reduces fuel fumes and thus the chance of an accidental explosion. All tanks on the aircraft are self sealing and feature flame resistant overflow and exhaust venting. Single point fueling and de-fueling can be performed from the starboard side of the forward fuselage Figure 14.3. This fueling point shares common lines with the Air Force retractable fueling boom port (Figure 14.4) located on the upper portion of the same segment of forward fuselage. Both ports offer fueling rates as high as 1100 gpm (4164 lpm), the maximum KC-10 Fuel Probe refueling rate (Table 10.II). Fuel is then power transferred to tank three and four. From tank four it is distributed to wing tanks one and two. Figure 14.3 - Fuel System Architecture Figure 14.4 - Retractable in-flight refueling boom ports, F22, F-117, B-2 92
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SAWE Paper No. 3232 Category No. 10
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Table of Contents Abstract_________
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List of Figures Figure 1.1 - Design
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Figure 13.4 - Rectilinear Vision Pl
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Nomenclature AIAA American Institut
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α Angle of Attack, degrees, rad.
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Table 1.II - Summary of Design Requ
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Figure 1.3 - F-15 Strike Eagle F-11
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Table 1.III - Comparison of the F-1
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Many of the equations buried in the
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3 Configuration The current configu
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Another problem arises from the 20
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• Span = 54.7 ft • m.a.c. = 32
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4 Stealth Considerations As mention
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Table 4.I - Common Ground Radars Ra
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30 20 10 0 -10 -20 -30 -40 -50 1 GH
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5 Aerodynamics The major aerodynami
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1 GHz. 40º LE Sweep 10 GHz. 40º L
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5.3 Wing Thickness The effect of wi
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5.4 Airfoil The NACA 65A-003 airfoi
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1 Section Lift Coefficient 0.9 0.8
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90 80 Wing Cross Sectional Area (ft
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6 Propulsion In developing the prop
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Table 6.II - RFP Dimensions Compare
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38 Figure 6.1 - VAATE Goals
Page 51 and 52: TSFC 3.0 2.8 2.6 2.4 2.2 2.0 1.8 1.
Page 53 and 54: Deflection Angle Analysis for Mach
Page 55 and 56: Figure 6.8 - Cost Association with
Page 57 and 58: The inlet has a boundary layer dive
Page 59 and 60: 7 Materials and Structure The overa
Page 61 and 62: Vertical Attachment Points Horizont
Page 63 and 64: 8 Landing Gear Landing Gear design
Page 65 and 66: steel. This means that more braking
Page 67 and 68: Table 9.II - Final Component Weight
Page 69 and 70: throughout the 5-hour mission. Usin
Page 71 and 72: 10 Stability and Control To initial
Page 73 and 74: difference in neutral point and cen
Page 75 and 76: 40 30 20 10 0 -10 -20 -30 -40 -50 2
Page 77 and 78: The Vendetta configuration utilizes
Page 79 and 80: -0.6 -0.4 UNSTABLE NEUTRAL -0.2 Lif
Page 81 and 82: Validation of an aircraft design su
Page 83 and 84: consumption. The main aspects of th
Page 85 and 86: In addition to the performance requ
Page 87 and 88: 70,000 Altitude (ft) 60,000 50,000
Page 89 and 90: 11.4 Mission Requirements By comple
Page 91 and 92: Table 11.VIII - Landing Flight Prof
Page 93 and 94: 11.7 Alternate Missions In addition
Page 95 and 96: 12 Payload Weapon internal layout d
Page 97 and 98: 13 Cockpit Cockpit Design began wit
Page 99 and 100: that could be used in landing and t
Page 101: 14 Systems The systems of the Vende
Page 105 and 106: 15 Manufacturing Several manufactur
Page 107 and 108: 16 Cost Analysis The final and perh
Page 109 and 110: Appendix Threats Chart Common Surfa
Page 111 and 112: Wing Break Point Fuel Aft Fuselage
Page 113 and 114: The Vendetta Design Team Chris Atki
Page 115 and 116: References 1. “Ejection Systems,
Page 117: 35. www.dfrc.nasa.gov/PAO/PAIS/HTML
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SAWE Report - Cal Poly San Luis Obispo

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