Page 69 - Military Technology 01/2018

Company Spotlight MT 1/2018 · 67

Florian Schildein

“Heavy Fuel Engine UAVs Can Play a Decisive

Role During Humanitarian Deployments”

Since 2009, 3W-International GmbH has with a two-stroke mixture of gasoline, 2%
offered heavy fuel (HF) engines, which Aspen oil, and 0.1% diesel valve clean-
could be used for helicopters, fixed-wing er. Kerosene, which is used for helicop-
aircraft and VTOL UAVs. ters, can likewise be used. “Our 2-stroke
HF engines can thus be very flexibly de-
ployed. The engine doesn’t need to be
The spectrum of the company’s 2-stroke purged when switching between fuel types,
HF engines ranges from the 1-cylinder en- which extremely simplifies the deployment.
gine with 3hp up to the 4-cylinder engine with Performance declines briefly at the moment
over 60hp. Moreover, an HF-driven WANKEL when fuels are switched, but then quickly
engine was introduced in 2017. re-establishes itself at the same high level,”
The fuels that 3W-International HF engines he continues.
run on are JET A-I, JP-5, JP-8 and a 2-stroke HF engines are characterized here by a
mixture of 2% Aspen oil and 0.1% diesel high degree of reliability, which use of the
valve cleaner. International navies pushed the twin-spark (TS) version can boost. All en-
development of these drives. “In the 2000s 3W-740xi B4 TS HFE FI piston ported engine. gines beginning at 55ccm can be delivered
there were, unfortunately, various incidents (Photo: 3W-International) as a TS version. The two ignitions work in-
on aircraft and helicopter carriers involving dependently. Because of that, engines with
UAVs having been filled with the wrong fuel. the TS version achieve different benefits:
That’s why navy associations worldwide issued the instruction that only a The engine idles slower, it generally operates more quietly, and its safety
fuel suitable for aircraft, helicopters and UAS should be used worldwide,” and reliability increase in both single- and multiple-cylinder engines. When
Karsten Schudt, Managing Partner of 3W-International, tells MT. one ignition fails, the second ignition, working independently, ensures that
In addition, JET A-I, JP-5 and JP-8 are difficult-to-ignite fuels. “JET the engine continues to run with slightly reduced rpm. Moreover, depend-
A-1 has a 38°C flash point. Of course that’s especially important on ships, ing upon the engines’ use and care, maintenance intervals range between
where fire poses a very special danger,” he explains further. 400 and 600 hours.
Besides gasoline and HF engines, electrical drives are also employed HF engines from 3W-International can be used in all UAS systems. The
in today’s UAS. However, internal combustion engines enjoy advantages performance engines from Germany are used in both fixed-wing aircraft
particularly with the power-weight ratio because they alone enable a heavy and helicopters. “HF technology yields quite clear benefits for these UASs’
bearing load, great flight elevations, and long ranges. Modern injection operators,” Mr. Schudt emphasises.
technologies are able to reduce consumption values thereby further en- The engines are very flexible and reliable, and they diminish the costs
hancing these drones’ performances. “We’re continually working on im- of deployments. Simpler deployment planning is also possible thanks to
provements to our injection technology. In the autumn of 2017, we will be the fuel independence. On-site logistics is likewise less costly. “These
presenting a completely new solution to the market, which will massively cost savings, especially on the part of the employees needed to operate
improve the engines’ performance data at constant consumption,” the in- the UAS, are of interest for our customers. In the past year and a half,
dustry expert continues. the number of requests to integrate our engines into UASs intended for
HF-based internal combustion engines can demonstrate their strengths humanitarian-aid deployment has increased,” he asserts.
especially during missions for humanitarian purposes in disaster areas. In 2017, 3W-International enhanced its portfolio with the WANKEL
Most unmanned aircraft equipped with 3W-International engines are un- engine 3W-180 SRE Hybrid, which can also be used as an HF version,
armed and are deployed for reconnaissance and surveying tasks. This is and has 180ccm weighing 6.8 kilogrammes. In the high power version, at
explained by the engines’ performance data, because the heavier payload 7500rpm it delivers 38.5hp (nominal power 28hp at 6,000rpm). From this
necessitates more powerful engines for armed UAS. These reconnais- there results a power-to-weight ratio of 5.66hp/kg, with a fuel consumption
sance drones also come into use especially during disaster and humani- of 340g/kW at full load. The weight rises to 9.5kg when the engine is fitted
tarian deployments to provide a quick overview of the crisis region. UAVs with an electric motor (starter generator).
with HF drives can play a decisive role during these deployments. The “Requests for powerful drive units for helicopters have also increased
engines’ structure and technical specifications justify this. However, trans- steadily during the past year and a half. The WANKEL engine is an optimal
port tasks for first aid can also be accomplished with UASs. solution here precisely because it uses the least fuel in the high rotation-
The local infrastructure is, for the most part, completely destroyed in al-speed ranges such as those necessary in helicopters,” according to Mr.
crisis regions such as earthquake areas. Parts of the areas are often largely Schudt. WANKEL technology is also ideal for reconnaissance missions
inaccessible or accessible with great difficulty. Landing options for heli- because the engines run very quietly, thus imparting few vibrations to the
copters or aircraft must in part be re-established. The transport of food- flight system.
stuffs and medications for first aid is thus possible only to a limited extent The Managing Partner of 3W-International is convinced that the role of
because the degree to which land vehicles can be deployed is limited. UASs in humanitarian aid will increase strongly in future. “Today, many
Helicopters generally assume the main task. UAS can also play an im- NGOs regularly employ drones to supply the rural population or to quick-
portant role here even though their transport capacities are much smaller. ly transport urgent medical products in many African states. We’ve re-
“UAS can be quickly relocated to a crisis region, meaning that reconnais- ceived requests from South-east Asia for similar tasks. Meanwhile, sen-
sance tasks can be undertaken early on. You’re more independent since sitive goods such as blood bottles are now being transported in addition
only one pilot is need, who doesn’t necessarily need to be on site. The lim- to medications. We’ve basically got conditions similar to those in a crisis
ited use of autopilots is also feasible. The necessary on-site infrastructure area: rugged terrain, which only admits transportation with land vehicles
is minimal, and so are the deployment costs. Furthermore, HF-driven UASs to a limited extent, or large distances between hospitals and communities.
are also fuel-independent,” says Mr. Schudt, describing the possibilities. Capable UASs are ideal, cost-effective means of transport here and will be
The fuel independence in particular affords increased flexibility. able to further exploit their advantages in future with internal combustion
Fuel availability can restrict the use of aircraft. The military and aid or- engines.”
ganisations active in crisis regions should be assumed to make a suffi-
cient quantity of diesel and gasoline quickly available on site. Two-stroke
HF engines can be driven with the available gasoline since they operate Florian Schildein works at 3W International GmbH