Ikelos

1
Ikelos

• Virginia Tech and Loughborough University present

2001/2002 Interdisciplinary/International
Aircraft Design Project
2
Original Specification

• Key Requirements
• Aircraft fits on trailer
• Lightweight and Simple
• STOL or VTOL
• Land in 46m (150ft) over 5m obstacle
• Cruise gt 90 kts
• Range gt 150nm
• 1 Seat Aircraft

3
Initial Design Ideas

• Each group produced 3 concepts
• Counter-rotating Helicopter
• 2 Gyroplanes
• VTOL tilt duct
• Vectored jet
• Pusherprop
• Selected VTOL Tilt duct
• Most adaptable
• Most Original

4
Initial Concepts
VTOL Tilt Duct
Pusher Prop
5
Design Development

• Reviewed advantages and disadvantages of
• STOL
• VTOL
• Vectored Thrust
• Modified Design to
• STOL as standard aircraft
• Vectored thrust option

6
Revised Specification

• 46m (150ft) ground roll
• Meet SSTOL requirement 150m (500ft) over
• 15m (50ft) obstacle
• Cruise speed to be competitive with GA
  aircraft
• 110kts 150kts
• Range - 500nm at cruise speed
• 2 Seat Aircraft

7
Configuration
8
Configuration
9
Fuselage Structure Layout
10
Wing Structure Layout
11
Wing Detachment

• Trailer criteria of 2.2m max. width
• Front Wing
• I section spars overlap in fuselage, bolted
  together in hollow box structure
• Rear Wing
• Connected to top of tail using two 3-way
  brackets
• Vertical Spars
• Bolted to outer ribs using hollow tube
  connections

12
Materials

• Glass epoxy skin on wings and fuselage
• Skin is honeycomb sandwich
• Kevlar reinforcement on fuselage bottom and
  lower wing skins
• Structure framework of carbon fiber with metal
  reinforcements in critical areas
• Aluminum firewalls and steel undercarriage

13
V-n Diagram
14
Manufacturing

• Planes assembled in individual bays
• Composites used where possible
• Internal skeleton
• Assembly team at each bay
• Team unity and pride in work
• Important due to the complexity of wiring,
  controls, and electronics

15
Tornado VLM

• Non-planar vortex lattice method
• Incorporates various wing features

16
Wing Layout

• Box-wing design
• Front wing twisted
• Unswept inboard TE flap

17
Lift Characteristics

• Based on forward wing area
• CLMAX 4.19
• Leading edge devices
• Front wing flapped
• Fowler te flaps, fixed vane

18
Drag Characteristics

• Induced drag reduction
• CD0 .045 in cruise

INLETS AND OUTLETS
WINGS
SIDE PLATES
VERTICAL TAIL
35
3
12
4
12
OTHER
17
5
FUSELAGE
24
DUCTS
UNDERCARRIAGE
19
Stability and Control

• Static Stability
• Design Criteria Acceptable static margin in
  all configuration, FAR 23 compliance
• Final Configuration balanced (positve Cm0L)
  with positive pitch stiffness (negative Cma)
• Lateral-Directional stability satisfied but
  nearly neutral to retain maneuverability
• Dynamic Stability
• Design Criteria MIL-F-8785C specifications
  with Level 1 flight qualities

20
Control Surfaces

• Aircraft equipped with standard elevators,
  ailerons, and rudder

21
Trim Diagram
22
Control Forces

• Used Roskam methods to determine control
  forces
• Analysis shows that FAR 23 stick force limits
  are satisfied

23
CG Excursion Graph
24
CG Travel in MTOM Flight
Conclusion Stable Aircraft
25
The Rand Cam Engine

• Innovative diesel rotary engine
• Inherently simple, no pistons, timing values,
• spark plugs
• Uses a system of axial vanes that rotate in a
• cam shaped housing

26
The Rand Cam Engine

• Light weight High power to weight ratio
• Fuel efficient
• Costs similar to that of an equivalent automotive
  engine
• Low noise
• Very little vibration
• Low maintenance

27
Engine Layout
28
Ducted Fans

• Higher thrust per horsepower for a given diameter
  than a propeller
• Better performance at low speeds than propellers
  no recirculation at the tips
• Quieter than propellers noise damping material
  used in ducts
• Duct provides an additional safety feature.
• Duct diameter 0.92 m (3 ft)
• Fan consists of 5 rotor blades and 12 stator
  blades
• Fans attached to engine via a 12 helical spiral
  bevel gear
• Low noise 60dBs. Tip speed 113 m/s (370 ft/s)

29
Thrust Calculations

• Static thrust calculated using disc actuator
  theory
• Dynamic thrust found using general thrust
  equation
• Efficiency found by reading from chart of
  empirical data charts

30
Thrust Curve
31
Cockpit Layout
32
Cockpit

• Designed for 95th percentile male (tallest
  male) and adjustable to 5th percentile female
  (shortest female)
• Adjustable seats and rudders
• Center stick
• Energy absorbing Confor foam seats for high
  impact landing
• Canopy door allows ease of entrance
• Harness seatbelts for pilot and passenger
  safety

33
Avionics

• Base Cockpit Instrumentation
• EFIS
• Display
• EFIS Computer
• AHRS Computer
• PFD Engine instrumentation
• Transmission Reception devices
• NAV/COMM Radio
• Mode A/C Transponder

34
Avionics
35
Systems

• Safety
• Anti-lock brakes
• Ballistic parachute
• 5 Point seat belt
• Control surface actuation
• Mechanical
• Canopy
• Single piece with gas struts

36
Systems

• Cabin Conditioning
• Warm air taken from oil cooler
• Mixed with external air
• Provides de-misting (de-frosting)
• Electrical
• Standard 28V system
• 120 Ampere alternator

37
Landing Issues

• Original Specification 46m (150ft) landing
  distance over 5m obstacle

If stall speed 25kts and free roll 1
second free Roll 15m
38
Revised Specifications

• Target ground roll 46m (150ft)
• Total landing and take off NASA SSTOL
• 9o Glideslope used in NASA analysis

39
Landing and Take-off
Landing
Target
Take-off

• Target met at all take-off weights
• Landing Target met with 1 pilot and full fuel

40
Landing and Take-off

• Certification over 50ft (15m) obstacle
• SSTOL requirement met at all conditions

Target
Landing
Take-off
41
Cruise Performance

• Max Range Full Payload 650nm _at_ 80 knots
• 500 nm _at_ 124 knots
• Max Endurance over 8 hours _at_ 64 Knots

42
Climb Performance

• 10,000 ft in under 10min _at_ 85 and 90 Knots
• Max Climb 1364 ft/min _at_ 90 Knots

43
Turn Rates

• Max Turn Rate 70 Deg/sec _at_ 57 knots

44
Mass Breakdown

• kg lb
• Structure 235 486 37
• Propulsion 112 246 18
• Equipment 28 62 4
• OEM 375 794 59
• Payload 182 400 29
• Fuel 78 172 12
• MTOM 635 1366 100

45
Aircraft Cost Analysis

• Target price luxury sports car
• US 200,000 price ceiling
• Costing analysis is conducted using Roskam
• methods
• Anticipated cost reductions from avionics
  development are not yet considered

46
Certification Philosophy

• Certify under Joint Airworthiness Requirements
  Very Light Aircraft Category
• Federal Airworthiness Requirements
• Sport aviation category
• Revise requirements

47

Strengths
48
Strengths
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Weaknesses and Threats

• Risk Unproven propulsion system
• Control authority in landing more analysis
  required
• Specialized product for SSTOL market.

50
Opportunities

• Range of aircraft basic to high performance
• High performance options
• More advanced avionics
• Thrust vectoring
• Circulation control
• Higher end of Market
• Military or law enforcement possibilities

51
Conclusions

• Innovative modern technology employed.
• Large scope for adaptability
• Configuration set but still opportunity for
  adjustments
• Project still in progress