Currawong Engineering Announces New Hybrid Propulsion System for Heavy Fuel UAVs

Cortex Heavy Fuel Hybrid System

Cur­ra­wong Engi­neer­ing has launched the Cor­tex Heavy Fuel Hybrid Sys­tem, a two-stroke hybrid engine for heavy fuel unmanned aer­i­al vehi­cles (UAVs) with indus­try-lead­ing pow­er den­si­ty, inno­v­a­tive new fuel and Cur­ra­wong-devel­oped pow­er elec­tron­ics.

Cor­tex Heavy Fuel Hybrid Sys­tem is a two-stroke hybrid engine for UAVs.

Key features of the engine

The hybrid archi­tec­ture allows the engine to pow­er the onboard elec­tri­cal sys­tems and charge the bat­ter­ies while still pro­vid­ing thrust for flight. In case high pow­er is required, the motor and bat­ter­ies can work togeth­er to increase the over­all pow­er. It also reduces the over­all weight of the propul­sion sys­tem by reduc­ing the num­ber of bat­ter­ies need­ed to sus­tain flight dura­tion. Ener­gy can also be direct­ed from the bat­tery sys­tem to the engine to increase pow­er dur­ing flight and restart the engine in the air.

Hybrid Transmuter

To bal­ance the flow of ener­gy through the sys­tem, Cur­ra­wong devel­oped what is called “hybrid trans­muter» based on the extreme­ly pow­er­ful ESC of the Veloc­i­ty series. The hybrid trans­muter man­ages bat­tery charg­ing, chang­ing UAV load require­ments, and is also able to deter­mine whether to sup­ply pow­er from the motor to the bat­ter­ies or from the bat­ter­ies to the motor. All of this hap­pens auto­mat­i­cal­ly, mak­ing the Cor­tex sys­tem an ide­al bat­tery replace­ment.

Triplex fuel pump

Heavy Fuel, or more specif­i­cal­ly, sta­ble heavy fuel, is con­stant­ly striv­ing to cre­ate a safer envi­ron­ment for Cur­ra­wong’s work­force. The com­pa­ny was able to show that UMAN-VP4F per­forms well as a spark igni­tion fuel in a Corvid-50 engine with very clean com­bus­tion. The out­put pow­er of such an engine is com­pa­ra­ble to that of a gaso­line inter­nal com­bus­tion engine. The UMAN-VP4F requires a fuel pres­sure of 8–10 bar, which is ide­al for using the spe­cial­ized Triplex fuel pump devel­oped by Cur­ra­wong engi­neers.

The Triplex’s unique three-pis­ton fuel pump design pro­vides high pres­sure, smooth fuel deliv­ery, while a tight­ly inte­grat­ed con­trol sys­tem allows pre­cise fuel deliv­ery. The Triplex pump is self-prim­ing and is able to mea­sure fuel con­sump­tion with an accu­ra­cy of <1%.

Specification

Engine’s type:

two-stroke, hybrid

Vol­ume:

50 cc

The weight:

4.7 kg (engine, gen­er­a­tor, low noise exhaust sys­tem, cool­ing sys­tem, insu­lat­ing sup­port, EFI includ­ing Triplex pump, con­vert­er and wiring har­ness)

Fuel type:

heavy fuel UMAN-VP4F

Fuel con­sump­tion:

600 g/kWh (elec­tric) at 5000 rpm and 50% throt­tle* (* This fuel may dif­fer from the above per­for­mance fig­ures and depends on the appli­ca­tion)

Pow­er:

2.4 kW (elec­tric) at 7500 rpm

Gen­er­a­tor:

130 kV

Con­vert­er volt­age:

60V/14S

Con­vert­er cur­rent (continuous/peak):

50A/300A

Con­vert­er pow­er:

7.5 kW

Igni­tion:

CDI

Cool­ing:

air

Time Between Over­haul (TBO):

350 hours

Rec­om­mend­ed max. weight:

40 kg

Slave. trans­duc­er tem­per­a­ture range:

-20°C to 100°C

Full tech­ni­cal doc­u­men­ta­tion pro­vid­ed by the devel­op­er is avail­able here.

Those. drawing

Tech­ni­cal draw­ing of a two-stroke hybrid engine from the devel­op­er:

Equipment

The devel­op­er put the fol­low­ing com­po­nents in the kit with the engine:

1. Igni­tion block
2. Spark plug
3. fuel injec­tor
4. crank sen­sor
5. Throt­tle ser­vo
6. Tem­per­a­ture sen­sors, includ­ing cylin­der head tem­per­a­ture (CHT; Cylin­der Head Tem­per­a­ture) and man­i­fold air tem­per­a­ture (MAT; Man­i­fold Air Tem­per­a­ture) sen­sors
7. Man­i­fold pres­sure sen­sor
8. Throt­tle body and exhaust man­i­fold
9. Cool­ing chan­nel and cool­ing con­trol ser­vo

Availability and price

The Cor­tex Heavy Fuel Hybrid Sys­tem will be avail­able to order from Sep­tem­ber 2022. At what price it will be sold, the devel­op­er has not yet dis­closed. Ship­ping will be world­wide.

Application

With this inno­v­a­tive fuel, the Cor­tex sys­tem will be pri­mar­i­ly rel­e­vant for naval appli­ca­tions, and the hybrid nature of the engine allows for a wide range of appli­ca­tions in var­i­ous vehi­cles.

About the developer

Cur­ra­wong Engi­neer­ing Pty Ltd is a glob­al leader in pow­er­train sys­tems for unmanned aer­i­al vehi­cles (UAVs) for both mil­i­tary and com­mer­cial appli­ca­tions. Cur­ra­wong’s first offer­ing was a Corvid-29 engine includ­ing a cus­tom induc­tion sys­tem, fuel injec­tion sys­tem, low noise exhaust and pow­er sup­ply. The sec­ond Corvid-50 engine sys­tem was devel­oped to meet the rapid­ly grow­ing UAV mar­ket with heav­ier pay­loads.

Cur­ra­wong has devel­oped a CAN ser­vo dri­ve that pro­vides a com­plete closed loop dri­ve sys­tem with real-time posi­tion feed­back. The com­pa­ny has also devel­oped a pow­er­ful and reli­able ESC Veloc­i­ty elec­tron­ic speed con­troller. These elec­tron­ic sys­tems are net­worked via the CAN stan­dard along with the engine con­trol unit, pow­er sup­ply, autopi­lot and pay­load. Cur­ra­wong’s pro­pri­etary soft­ware, cEQUIP, pro­vides an inter­face for real-time con­fig­u­ra­tion and data log­ging of elec­tron­ic sys­tems. Cur­ra­wong also offers spe­cial­ized machin­ing ser­vices and engi­neer­ing design con­sul­tan­cy to local and inter­na­tion­al clients.

All the best! And safe flights!