Vehicles Research and Development Establishment, Ahmednagar
ENGINE DEVELOPMENMT FOR
UAV APPLICATIONS.
EXPERIENCES AND CHALLENGES.
Dr C.P.RAMANARAYANAN
Vehicles Research and Development Establishment, Ahmednagar
UNMANNED AERIAL VEHICLE
UAV is an aerial vehicle capable of sustained flight without need
for a human operator onboard.
Although UAV’s are mostly used in military applications nowadays,
the UAV’s can also perform such scientific, public safety and commercial
tasks as image acquisition of disaster areas, map building, communication
relays, search and rescue, traffic surveillance and so on..
EUROUVS has drawn up a classification of UAV systems:
1. Micro and Mini UAV’s
2. Tactical UAV’s – Close/Short/Medium/Long Range/MALE
3. Strategic UAV’s – HALE
4. Special Task UAV’s – Lethal/Decoys/Stratospheric/Exo-
Stratospheric
Vehicles Research and Development Establishment, Ahmednagar
UAV ENGINE TECHNOLOGY
• Engines for unmanned aerial vehicle applications that
require 120 hp or less are typically based on spark ignition,
reciprocating internal combustion engines using gasoline or
similar fuels.
• The engine construction includes 2-stroke, 4-stroke
(naturally aspirated and boosted) as well as rotary style
engines.
• New requirements are also dictating the need for the
use of new light weight materials and multi fuel capabilities.
UAV ENGINES - SPECIAL REQUIREMENTS
Vehicles Research and Development Establishment, Ahmednagar
• High Power to weight ratio.
- Ratio of the order of 2 or more.
• Long Endurance
– Mission duration of 20-50 hours or more.
• Duty Cycle
– Demanding duty cycle with high Altitude take off.
Compactness
– Low Volume
• Simple Maintainability
– Robustness, lower skills ground crews.
• Signature
– Low heat signature/EMC
Vehicles Research and Development Establishment, Ahmednagar
POWER PACK FOR VARIOUS CLASS OF UAV’s
ENGINES FOR UAV’s
UAV TYPE ENGINE TYPE POWER RANGE (HP)
Micro Electrical 1
Mini Piston (2 X 2) 1 – 20
TAC, CR/LE Rotary (WANKEL) 20 – 90
MALE Piston (4 X 4) 90 – 250
MALE Turbo – Prop 250 – 500
HALE / TCUAV Turbo – Jet / Fan Above 500
Vehicles Research and Development Establishment, Ahmednagar
VRDE – ASSOCIATION IN UAV ENGINES
VRDE has been tasked for development of mini UAV’s
of less than 150kg class.
It is also involved in the development of small, low
weight, high-specific power output engines.
VRDE has successfully developed a few two stroke
engines and have been tested.
Development of Wankel Rotary Engine was taken up in
collaboration with NAL and ADE and has been realised
successfully with completely indigenous technologies.
Currently development of engines of higher class is in
progress.
Vehicles Research and Development Establishment, Ahmednagar
VRDE IN UAV ENGINE DEVELOPMENT
The salient features of the engines developed include:
• High power to weight ratio
•Hard chrome plated aluminum cylinders
•Diaphragm type carburetors for all position operation
•Multi-piece crankshaft.
Vehicles Research and Development Establishment, Ahmednagar
SPECTRUM OF 2-STROKE UAV ENGINES
Four-cylinder 37 hp engine Two-cylinder 21 hp engine
Single-cylinder 11 hp engine TBI system for 2-cylinder engine
Vehicles Research and Development Establishment, Ahmednagar
VRDE – ASSOCIATION IN UAV & AERIAL ENGINES
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rust (k
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Thrust Vs RPM: Single, Twin and Four-cyl engine
Four-cylinder
Two-cylinder
Single cylinder
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Fuel Consumption Vs Speed Four Cylinder
Two Cylinder
SingleCylinder
Vehicles Research and Development Establishment, Ahmednagar
FLIGHT ROTARY ENGINE FOR NISHANT UAV
• The engine is jointly designed and developed by NAL, VRDE and ADE.
• The engine weighs less than 30 Kgs, and has high power to weight ratio in
single rotor category.
• The engine has a power of 55 hp and can also be used for powering smaller
air vehicles.
Vehicles Research and Development Establishment, Ahmednagar
VRDE – ASSOCIATION IN UAV & AERIAL ENGINES
Power output 55HP@ 8000rpm
Swept Volume 324 CC
Compression Ratio 9.2
Min SFC 250 gm/bhp-hr
Idle Speed 2700-2900 rpm
Ignition System Electronic 28v CD Ignition
Cooling Water cooled Housing &
air cooled rotor
Carburetor Diaphragm Type
Lubrication Total loss type lubrication
Weight (Dry) 26 kg
55 HP ROTARY ENGINE
Vehicles Research and Development Establishment, Ahmednagar
VRDE – ASSOCIATION IN UAV & AERIAL ENGINES
TESTING OF ROTARY ENGINE
Various testings carried out:
- Thrust cradle testing
- Dynamometer testing
- Running-in testing
- Endurance testing (Based On JAR Cycle/ Cemilac Reco. Cycle) - Mission cycle testing
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Thrust Cradle &
Dynamometer testing
Vehicles Research and Development Establishment, Ahmednagar
VRDE – ASSOCIATION IN UAV & AERIAL ENGINES
INTEGRATION & FLIGHT TRIAL
Integration of Engine on
UAV ‘Nishant’
Flight testing on ‘Nishant’
Vehicles Research and Development Establishment, Ahmednagar
4-STROKE ENGINE FOR MALE UAV
• VRDE is currently working on horizontally opposed 4-cylinder
4-stroke turbocharged SI engine.
• The engine will develop thrust for the take off weight of about
2000kg.
Vehicles Research and Development Establishment, Ahmednagar
BROAD SPECIFICATION PORPOSED ENGINE.
TARGET 4-STROKE ENGINE
Type of the engine
4cylinder, 4 stroke horizontally
opposed, spark ignited
reciprocating piston engine with
turbocharger
Take off power 120 ± 3 BHP with turbocharger at sea
level
Maximum continuous power 105 ± 3 BHP with turbocharger at
sea level
Maximum operating altitude 36000 ft
Specific fuel consumption 275 ± 5 g/kWh at max. continuous
throttle
Dry engine weight 75 ± 2 Kg
Max engine speed 6000 RPM
Endurance 36+ hours
Operating temperature -40°C to +55° C
Maximum propeller speeds 2300 to 2500 rpm
Vehicles Research and Development Establishment, Ahmednagar
WORLD/INDIAN SCENARIO IN MALE UAV ENGINES
• Most of the MALE UAVs are fitted with four-stroke four-cylinder engines
• For 125 HP engine for MALE UAV, a 1500 – 2000cc engine will be
adequate for meeting the requirements
• Four-cylinder Horizontally opposed four-stroke engine configuration
with Turbocharger will serve the purpose of propulsion system for
INDIA’s version of MALE UAV ‘RUSTOM’
ROTAX ENGINES LYCOMING ENGINES LIMBACH
(AUSTRIA) (USA) (GERMANY)
Vehicles Research and Development Establishment, Ahmednagar
4-STROKE ENGINE FOR MALE UAV - RUSTUM
Critical factors/technologies involved:
• Turbo-charging technology for SI Engine
• Multi Point Fuel Injection (MPFI) for multi-cylinder four-stroke
engine.
• Composite coating technology on aluminium alloy.
• Application of High specific strength material like Maraging
steels and Al alloys.
Vehicles Research and Development Establishment, Ahmednagar
FUTURE UAV ENGINES
DIESEL UAV ENGINES
Highly Fuel-efficient than present gasoline engines
Strategically suitable for single fuel concept
HYDROGEN OPERATED ENGINES
Suitable for very high altitude operation
Highly complex challenging technology
Very long endurance is possible
Vehicles Research and Development Establishment, Ahmednagar
DIESEL ENGINES FOR UAV’s
REQUIREMENT OF DIESEL ENGINE FOR UAVs
The vast majority of UAVs are using currently utilizing gasoline fuels
(e.g. Hunter, Shadow, Predator etc.)However, these engines can be
improved to Diesel version due to following:
1. Causes a specific gasoline logistics train since most military vehicle use
diesel fuel.
2. Gasoline vapor is explosive, hence is a hazard to the aircraft and ships
that transport it.
3. Gasoline engines are less efficient than heavy fuel engines thus
providing shorter flight/loiter times.
Vehicles Research and Development Establishment, Ahmednagar
ADVANTAGES OF DIESEL ENGINES
Reliability
Maintenance
Turbocharge
and supercharge
Fuel economy
Durability
Efficiency
Vehicles Research and Development Establishment, Ahmednagar
CHALLENGES IN HEAVY FUEL ENGINES
High peak pressure
Produce black soot
Expensive
DIESEL UAV ENGINES DEVELOPERS
GAP DIESEL ENGINE NASA DEVELOPMENT USA
DYNA CAM ENGINE
ECO–MOTORS DIESEL ENGINE GERMANY
AUSTRO ENGINE AE 300 AUSTRAIN
DELTA HAWK DIESEL ENGINE USA
CENTURIONS GERMANY
DIESEL AIR LIMITED UK
Vehicles Research and Development Establishment, Ahmednagar
THANK YOU