Wave disk engine
Encyclopedia
A wave disk engine is a type of pistonless rotary engine
being developed at Michigan State University
and Warsaw Institute of Technology. The engine has a spinning disk with curved blades. Once fuel and air enter the engine the rotation of the disk creates shockwaves that compress the mixture. When ignited, the burning mixture expands, pushing against the blades, causing them to spin. The spinning of the disk itself opens and closes intake and exhaust ports. A prototype was reportedly demonstrated in March 2011. The proposed concept was called Radial Internal Combustion Wave Rotor.
to transfer energy between a high-energy fluid to a low-energy fluid, thereby increasing both temperature and pressure of the low-energy fluid (also called pressure wave machines or pressure exchangers).
s, the efficiency of a wave disk engine is governed by the temperature difference between the hot and cold sides. Compared to a conventional piston engine (reciprocating engine
), a wave disk engine works at higher peak temperature, which theoretically makes it more efficient. The design also works without a cooling system, saving weight. Compared to turbine
based systems, the rotational speed of the wave disk engine is lower, which creates lower stress on material.
Earlier wave rotor implementations were mainly axial flow, where the scavenging
process of returning hot compressed air back into the turbine is complex. The wave-disc engine uses a radial and circumferential flow, using centrifugal forces for scavenging. Curved channels provide greater length for the same disc diameter compared to straight channels, allowing the travel times of the waves to be tuned properly.
s, which could free up about 1,000 pounds of weight. It promises up to 3.5 times more efficient (to 60%), 30% lighter, 30% cheaper to manufacture than an equivalent conventional piston engine, and reduce emissions
by 90%.
Michigan State University
and Warsaw Institute of Technology researchers claim to have a prototype wave-disk engine and electricity generator that could replace current backup generator technology of plug-in electric hybrid vehicles. The research team is led by Associate Professor of Mechanical Engineering Norbert Müller and has been given $2.5 million funding from the United States Department of Energy
's ARPA-E
program. Müller's team hopes to have a vehicle-sized 25 kilowatt wave disc engine/generator ready by the end of 2013.
Pistonless rotary engine
A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does, but instead uses one or more rotors, sometimes called rotary pistons...
being developed at Michigan State University
Michigan State University
Michigan State University is a public research university in East Lansing, Michigan, USA. Founded in 1855, it was the pioneer land-grant institution and served as a model for future land-grant colleges in the United States under the 1862 Morrill Act.MSU pioneered the studies of packaging,...
and Warsaw Institute of Technology. The engine has a spinning disk with curved blades. Once fuel and air enter the engine the rotation of the disk creates shockwaves that compress the mixture. When ignited, the burning mixture expands, pushing against the blades, causing them to spin. The spinning of the disk itself opens and closes intake and exhaust ports. A prototype was reportedly demonstrated in March 2011. The proposed concept was called Radial Internal Combustion Wave Rotor.
Background
The very first type of wave rotor was developed in the 1950s. Wave rotors utilize shock wavesShock Waves
Shock Waves, , is a 1977 horror movie written and directed by Ken Wiederhorn...
to transfer energy between a high-energy fluid to a low-energy fluid, thereby increasing both temperature and pressure of the low-energy fluid (also called pressure wave machines or pressure exchangers).
Operational principles
As with all heat engineHeat engine
In thermodynamics, a heat engine is a system that performs the conversion of heat or thermal energy to mechanical work. It does this by bringing a working substance from a high temperature state to a lower temperature state. A heat "source" generates thermal energy that brings the working substance...
s, the efficiency of a wave disk engine is governed by the temperature difference between the hot and cold sides. Compared to a conventional piston engine (reciprocating engine
Reciprocating engine
A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types...
), a wave disk engine works at higher peak temperature, which theoretically makes it more efficient. The design also works without a cooling system, saving weight. Compared to turbine
Turbine
A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...
based systems, the rotational speed of the wave disk engine is lower, which creates lower stress on material.
Earlier wave rotor implementations were mainly axial flow, where the scavenging
Scavenging (automotive)
In automotive usage, scavenging is the process of pushing exhausted gas-charge out of the cylinder and drawing in a fresh draught of air ready for the next cycle....
process of returning hot compressed air back into the turbine is complex. The wave-disc engine uses a radial and circumferential flow, using centrifugal forces for scavenging. Curved channels provide greater length for the same disc diameter compared to straight channels, allowing the travel times of the waves to be tuned properly.
Current status
The "wave-disk engine" has the potential to have better energy efficiency compared to normal internal combustion engine designs and can potentially save weight. Possible applications include charging batteries in hybrid vehicleHybrid vehicle
A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles , which combine an internal combustion engine and one or more electric motors.-Power:...
s, which could free up about 1,000 pounds of weight. It promises up to 3.5 times more efficient (to 60%), 30% lighter, 30% cheaper to manufacture than an equivalent conventional piston engine, and reduce emissions
Exhaust gas
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel fuel, fuel oil or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack or propelling nozzle.It often disperses...
by 90%.
Michigan State University
Michigan State University
Michigan State University is a public research university in East Lansing, Michigan, USA. Founded in 1855, it was the pioneer land-grant institution and served as a model for future land-grant colleges in the United States under the 1862 Morrill Act.MSU pioneered the studies of packaging,...
and Warsaw Institute of Technology researchers claim to have a prototype wave-disk engine and electricity generator that could replace current backup generator technology of plug-in electric hybrid vehicles. The research team is led by Associate Professor of Mechanical Engineering Norbert Müller and has been given $2.5 million funding from the United States Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
's ARPA-E
ARPA-E
ARPA-E, or Advanced Research Projects Agency-Energy is a United States government agency to promote and fund research and development of advanced energy technologies...
program. Müller's team hopes to have a vehicle-sized 25 kilowatt wave disc engine/generator ready by the end of 2013.
External links
- Numerical investigation of the Wave Disk Micro-Engine concept - International Journal of Gas Turbine, Propulsion and Power Systems December 2008, Volume 2, Number 1
- ARPAe site for Michigan State University: Wave Disk Engine
- YouTube: Faculty conversations: Norbert Mueller
- POPSCI article on shockwave generator
- New Scientist article on shockwave generator