Raptors final pres


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Raptors: COIN ISR UAS: 

Raptors: COIN ISR UAS ASE 261K/161M Aircraft Design – Spring 2007

Team Members: 

Team Members Vikram Garg – Team Lead Jacob Santos – Concept of Operations Cuong Tran – Payload Usbaldo Fraire – Aerodynamics / Performance Charlie Rogers – Propulsion / Configuration Adam Blanchard - Mass Properties / Trade Studies


Summary Objective – Design a UAS for customer defined COIN ISR mission Developed a mission Concept of Operations Developed individual concepts based on the requirements Optimized individual concepts and selected one based on cost and risk criteria Optimized chosen concept and surveyed its feasibility Summary


Agenda Problem Description and Definition - Vikram Requirements, Trade Studies & Config Selection – Adam Physical description and performance of air vehicle – Usbaldo Functional Description – Jacob Performance & Parametric Substantiation – Cuong Technical Risks & Conclusions - Charlie Agenda


Problem Definition


Forward based operations from 2000 ft hard surface at 3Kft MSL UAS shall provide continuous (24x7) day/night/under weather near real time close air support (CAS) within 100 nm x 100 nm operations area UAS shall simultaneously support of 10 SOF units and/or COIN operations, each located within individual 10 nm x 10 nm combat areas UAS shall be based within 70 nm of farthest combat area UAS shall resolve range of ground moving targets to 10 m anywhere within combat areas and transmit detection data within 2 minutes UAS shall provide once per hour, on demand positive identification of one selected target per combat area (req’d resolution = 25 cm) and transmit imagery to base and/or SOF units within 3 minutes of tasking Consider ConOps survivability effects Problem Description


Assume 4 of 10 combat areas are in corner locations, other 6 are uniformly distributed Problem Description


Defined Requirements


Defined Requirements Payload Defined Requirements UAS shall resolve range of ground moving targets to 10 m anywhere within combat areas - transmit detection data within 2 minutes Positive ID of 0.25 x 0.25 m target once per hour - within 3 minutes of tasking Payload installation weight factor = 1.33 Payload installation volume factor = 1.95 Non-scanning EO/IR @ Frame rate = 1 Fr/s Communication Defined Requirements Sensors, not the system status, drive overall bandwidth requirement Must maintain communication with UAV 100% of the time Communications bandwidth sizing factor = 1.15 SatCom has 40+ msec lag time Both the control station and ground units must be able to communicate with the UAV Grey scale level = 8 (3 bits) Data Compression rate = 5:1


Defined Requirements Parametrics Defined Requirements Balanced Field Length 2000 ft Aerodynamics Defined Requirements 10% trim drag penalty for conventional tails, 0% for canard Loiter stall speed margin is 10 Propulsion Defined Requirements Generator Power = Total Payload Power * 2 = 7000 W Mass properties Defined Requirements Installation Penalties: Weight: Prop: (includes fuel system) - Fixed: 125% engine dry weight - Variable Pitch: 130% Turboprop: (excludes fuel system) 165% dry weight Turbofan: (excludes fuel system) 120% dry weight Volume: - Installed Volume = 1.33 Uninstalled Volume - For internal payloads, communications equipment, internal portion of EO/IR volume - Installed Volume = 1.95 Uninstalled Volume 6% margin for weight growth 30% installation penalty on all other installed systems


Defined Requirements Configuration Defined Requirements Length ratios: 30% fuselage volume margin Air Vehicle Performance Defined Requirements Ps > 5 Miscellaneous Customer Defined Requirements


Individual Concepts and Selection


Team Concepts Design One: Design Two: Design Three: TB-Prop, Wing-body-tail ICProp, Wing-body-tail TB-Prop, Swept wings Design four: Design Five: Design Six: TB-Prop, forward swept wings TB-Fan, Wing-body-V tail TB-Prop, Unswept, V-tail


Trade Studies: - Viable air vehicle designs are based on trade studies - Trade studies allow for optimization - Same requirements must be adhered to for each concept: - Same: Mission, Payload, Takeoff Requirement, Operational Loiter, Reserves, etc. Trades for Each Design: - Empty weight versus: - Wing Loading - Cruise Speed - Altitude Trade Studies Trades for Team Design: - Empty weight versus: - AR - t/c - Fuselage Fineness Ratio


Wing Loading Trade Study Example Solver Fed Constraints Iterates FF and T/W Employed over Range of Values Result Minimum EW at Wo/Sref=34 psf


Remaining Individual Trade Studies Result Minimum EW at lowest allowable Vcr Result Minimum EW at lowest allowable Hcr


Team Concept Selection


Team Concept: Physical Description and Performance


Team Concept Design Loiter Mission 12 hrs at 255 nm Design Payload = 540 lbm EO/IR + SAR W0 = 1989 lbm WE = 974.6 lbm Design Fuel = 454 lbm W0/Sref = 21 psf AR = 11 Sref = 58.5 sqft Power = 420 Bhp TurboProp Retractable tricycle gear Balanced Field Lth = 3Kft Max endurance = 13.4 hrs Max range = 1397 nm Max speed @ hcr = 237 KTAS Ceiling altitude = 38 Kft D Side Retained payload EO/IR 10.24 max rotation vs. 10.1 req’d for takeoff Acft systems Fuselage length = 15.5’ wing span = 25.4’ TurboProp 158 lbm (uninstalled) a.c. @ 44.9% Engine diameter = 1.54’ Nacelle diameter = 1.92’ Landing gear retractable SAR antenna Leading edge wing sweep = 15 All fuel in wing tanks Plain flaps Horizontal tail leading edge sweep = 20º * * * m.a.c.= 2.4’ 2.8’ 2 vertical tails w/ leading edge sweeps = 25º Propeller Diameter: 6’


Air Vehicle Performance Overall Maximum range = 1397nm Maximum endurance = 13.4hrs - Takeoff distance (ground roll) =1000ft Initial rate of climb = 5331 ft/min Ceiling altitudes = 38Kft Landing loiter time = 45min Landing loiter speed = 112 KTAS Design mission Operational radius = 35.4 nm Cruise speeds = 139 KTAS @ 10Kft Operational loiter speed = 117 KTAS @ 10Kft Maximum speed at cruise altitude (Ps = 0) = 384 KTAS Total time on station = 12 hours Fallout mission Operational radius = 63.3 nm Operational loiter or dash distance = 8.07nm Cruise speed = 127 KTAS @ 4Kft Dash speed = 175KTAS @ altitude = 4Kft Maximum speed at dash altitude (Ps = 0) = 447 KTAS Total time on station = 12 hours


Functional Description


“X” marks the SOF Base Area of Operations (AOp) split into 4 quadrants One UAV for continuous GMTI coverage per quadrant executing a circular pattern about the center point Assume hexagon shape for remaining combat areas One UAV per combat area to obtain positive ID imagery every hour also executing a circular loiter pattern about the center 10nm 10nm Combat Area


ConOps AOp quadrants loiter pattern: 12hr shifts Geometry: circular loiter path about the center, r = 3.5nm - Creates a negligible area in the center of 38.5nm2 - Creates GMTI continuous area coverage of 98.5% Altitude: Driven by 80% threshold requirement - h = 10Kft MSL (7Kft above base operations) Loiter Speed: 117nm/hr 5+ rotations through loiter pattern within 1hr Negligible Area Est. sensor range R = 35.355nm A = 3927nm2 Quadrant, A = 2500nm2


ConOps 0 Engine start: t = 0min 1 Start taxi: t ≈ 5min (5min average eng. start time) 2 Start takeoff: t ≈ 25min (req’t #) 3 Start Climb: t ≈ 26min (req’t #), T0 ≈ 300 lbf (mean across team) 4 End Climb, start cruise: t ≈ 30min, h = 10Kft, v = 90KTAS 5 End cruise, Start loiter: t ≈ 50min, h = 10Kft, v = 70KTAS 6 End loiter: t ≈ 11.57hr, h = same, v = same 7 Sustained rate turn: h = same, 180º/5min turn 8 Start cruise: t ≈ 11.66hr, h = same, v = 90KTAS 9 End cruise: t ≈ 12.01hr, h = same 10 Start hold: 45min landing loiter 11 End hold, land: t ≈ 12.17hr (w/ 10min given to touch down & land) Notation Standoff – Distance to from loiter center to quadrant border, 25nm Operating Distance – Distance from base to loiter center, 35.4nm Terminology Quadrant UAV Mission Profile


ConOps Combat area loiter pattern: 12hr shifts Geometry: - hover about the center - circular pattern, r = 1nm Altitude: determined through positive ID imagery senor capabilities - EO/IR sensors will take and transmit imagery to either the base and/or ground units Speeds: 2 speeds required - Loiter speed, v = 112nm/hr - Pursuit speed for reaching and taking an image of a target, and transmitting that image to base or ground unit within 3 minutes of positive ID request - v = 175 nm/hr to travel from the center to the corner within 168s


ConOps 0,1 Engine start & taxi: t = 20min 2 Start takeoff 3 Start Climb: t = 0.2min 4 End Climb, start cruise: h = 4Kft v = 127KTAS 5 End cruise, start loiter: h = 4Kft v = 112KTAS 6 End loiter, start accel: 1occurence/hr 7 End accel, start ingress: v = 175KTAS 8,9 End ingress, Sustain rate turn 10 Obtain & transmit positive ID image 11 Start egress: v = 175KTAS 12 End egress, start cruise: h = 4Kft v = 115KTAS 13 Resume to loiter 1 14 Start loiter1: h = 4Kft v = 112KTAS 15 End loiter, start cruise v = 115KTAS 16 End cruise 17 Start hold: 45min landing loiter 18 End hold, land 1 loiter location (and path) same as 7 step 7-14 repeated 11 times Notation Mission Radius Operating Distance Combat area border - penetrate Border- Standoff Signifies that UAV returns to original loiter location after ID image is taken Standoff – Distance to from loiter center to combat area border, 5nm Operating Distance – Distance from base to loiter center, 63.6nm Ingress – To target at pursuit speed Max distance – 8.07nm Egress – From target at pursuit speed Max distance – 8.07nm Combat Area UAV Mission Profile Terminology


Payload and Performance Substantiation


Payload Synthetic Aperture Radar (SAR) Electro-optical/Infrared Sensor (EO/IR) Communication Systems Performance


Synthetic Aperture Radar (SAR) Sensor Sizing SAR GMTI requirement - detection (10m resolution, P95 detection = 4 pixels) Loiter at 10 Kft SL Lookdown angles are min=5 and max=45 SAR Sizing from Parametric Data Max range ~ 65.5 km, Volume ~ 6.5 cuft, Weight ~ 260 lbm, Power ~ 2250W SAR coverage area in a sample 50 sq nm quadrant “Blind spot” depends upon max=45 and is negligible 98.5% coverage Payload Performance


Electro-Optical/Infrared (EO/IR) Sensor Sizing EO/IR ID requirement - ID (25 cm resolution, P95 ID = 28 pixels) Loiter and ID at 4 Kft SL (SLR= 350m) Lookdown angle () = arctan(h/d) = arctan (304.8m/172m) = 60.56  IFOV req’d ~ 25.5 rad, FOV = (25.5+2.4)/29 = 0.962  = 16.8 mrad EO/IR Sizing from Parametric Data For EFL ~ 200mm: Turret Diameter  15 in, Turret height.  18 in, Volume  1.8 cuft, Weight  110 lbm, Power  700W AN/AAS-44(V) Lamps FLIR High performance multi-purpose thermal-imaging sensor Payload Performance


Sizing Non-scanning EO/IR and SAR communication system requirement EO/IR ID @ 1.048 Megapixel/0.75s3b/pixel1/5 = 0.84 Mbps SAR GMTI @ 8600 sqkm/day and 10 m res = 1.43 Mbps Size system with 15% margin for largest data requirement TOTAL Comm. Req. ~ 1.64 Mb/s LOS/SatCom Sizing from Parametrics Freq  10 GHz, RF power out  55W, RF power in  550W, RF module wt  40 lbm, RF module vol  1 cuft, LOS ant. wt  4.5 lbm, LOS ant. vol  0.125 cuft Total comms wt/vol/power per air vehicle ~ 45 lbm/1.125 cuft/550W L3 T-Series Model-U Airborne Data Link Dual LOS/SatCom System Payload Performance


Summary Payload Performance


Parametric Performance Comparisons


Parametric Performance Comparisons

Technical Risks & Solutions: 

Technical Risks & Solutions Propulsion System Availability Compare design engine to parametric data Aircraft Stability Want aircraft c.g. to be ahead of wing aerodynamic center 10% static margin Risks

Propulsion System Availability: 

Propulsion System Availability Original parameters Bhp0 = 156 ft*lbf/s SFCcr = 0.612 lbm/Hp*hr Hp0/Weng = 2.25 ft/s Weng-uninstalled = 69 lbf Risks

Propulsion System Availability Corrections: 

Propulsion System Availability Corrections Adjust SFC Adjust Bp0/Weng RR 250-C20B (Janes) Increase to fit curve Pick nearby point Match existing engine Previously 0.612, now 0.709 Match existing engine Previously 2.25, now 2.66 Adjust Shaft HP Match existing engine Previously 156, now 420 New Weng-uninstalled Previously 69, now 158 Risks

Aircraft Stability: 

Aircraft Stability Team configuration originally had aircraft c.g. behind wing aerodynamic center Unstable configuration High risk To correct, adjusted desired static margin Originally 10%, now 20% Risks

ABET criteria: 

ABET criteria Ethics – System could be used for spying and invade privacy. Need to regulate operational area. Sustainability – Allow for sensors, engine upgrades through robust design Economic – Designed for military use, can be exported to various foreign countries Environmental - Fossil fuel run, pollution issues Manufacturability – Assembly in one location Political – For government use only Social – Minimal Global Impact – Can be used by foreign countries since no sensitive technologies are used


Conclusions Gathered customer defined and derived requirements Created Concept of Operations Developed individual concepts based on the requirements Performed trade studies on individual concepts Selected one concept for the team based on: empty weight/fuel weight comparisons risk assessment Optimized team concept with existing engine Conclusions


Questions? Thank you Image: http://www.sukhoi.org/eng/planes/projects/bpla/complex/


* * * 10nm 10nm Combat Area


10nm 10nm Combat Area

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