The Diesel Air Dair 100 is an
opposed-piston
An opposed-piston engine is a piston engine in which each cylinder has a piston at both ends, and no cylinder head. Petrol and diesel opposed-piston engines have been used mostly in large-scale applications such as ships, military tanks, and f ...
diesel
Diesel may refer to:
* Diesel engine, an internal combustion engine where ignition is caused by compression
* Diesel fuel, a liquid fuel used in diesel engines
* Diesel locomotive, a railway locomotive in which the prime mover is a diesel engi ...
aircraft engine
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years ma ...
, designed and produced by Diesel Air Ltd of
Olney, Buckinghamshire
Olney (, rarely ) is a market town and civil parish in the unitary authority area of the City of Milton Keynes in Buckinghamshire, England. At the 2011 Census, it had a population of 6,477 people. It lies on the River Great Ouse and is the n ...
for use in
airship
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air.
In early ...
s,
home-built kitplane
Homebuilt aircraft, also known as amateur-built aircraft or kit planes, are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch", from plans, or from assembly kits.Armstrong, Kenn ...
s and
light aircraft
A light aircraft is an aircraft that has a maximum gross takeoff weight of or less.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 308. Aviation Supplies & Academics, 1997.
Light aircraft are used as utility aircraft co ...
.
[Tacke, Willi; Marino Boric; et al: ''World Directory of Light Aviation 2015-16'', pages 256-257. Flying Pages Europe SARL, 2015. ] The prototype was built in the 1990s and exhibited it at
PFA (now
LAA) airshows. Although Diesel Air engines have been fitted to an AT-10 airship and to a
Luscombe 8A monoplane,
production numbers have been very limited.
Design and development
The Dair 100 engine is a twin-cylinder
two-stroke
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of ...
, opposed-piston, displacement,
liquid-cooled
Liquid cooling refers to cooling by means of the convection or circulation of a liquid.
Examples of liquid cooling technologies include:
* Cooling by convection or circulation of coolant, including water cooling
* Liquid cooling and ventilat ...
,
diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-cal ...
direct drive design. It produces at 2500 rpm, with a
compression ratio
The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values.
A fundamental specification for such engines, it is measured two ways: the stati ...
of 18:1.
The engine has two cylinders and two crankshafts linked to four pistons, the combustion chamber formed between the crowns of the pistons. There are no poppet valves, each cylinder having a ring of ports at each end. In this "one-direction (uniflow)" engine these ports, respectively, admit air and expel exhaust gases. This design eliminates the need for a cylinder head and camshafts. Scavenging is assisted by a
centrifugal air pump, the pump also serving to provide a mild
supercharging
In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement.
The current categorisation is that a supercharger is a form of forced induc ...
effect. Fitment of an exhaust-driven
turbocharger
In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...
is permissible.
The engine may use either diesel fuel (DERV) or
Jet-A1
Jet fuel or aviation turbine fuel (ATF, also abbreviated avtur) is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for commercial av ...
kerosene (AVTUR). Jet-A1 is more readily available at airfields, but its reduced
lubricity
Lubricity is the measure of the reduction in friction and/or wear by a lubricant. The study of lubrication and wear mechanisms is called tribology.
Measurement of lubricity
The lubricity of a substance is not a material property, and cannot be me ...
(compared to diesel fuel) could mean that additional cylinder lubrication may be required. Fuel is
directly injected into each cylinder, pressure being supplied by a hydraulically-governed mechanical fuel pump.
Dry sump
A dry-sump system is a method to manage the lubricating motor oil in four-stroke and large two-stroke piston driven internal combustion engines. The dry-sump system uses two or more oil pumps and a separate oil reservoir, as opposed to a con ...
lubrication is by high pressure pump delivering oil to plain main bearings and con-rod bearings.
Applications
*
Advanced Airship Technologies Group AT-10 airship
*
Luscombe 8A
Specifications (Dair 100)
See also
*
Zoche aero-diesel
References
External links
*{{Official website, http://www.dair.co.uk/
Diesel Air aircraft engines
Two-stroke aircraft piston engines
Liquid-cooled aircraft piston engines
2010s aircraft piston engines