A motorjet is a rudimentary type of jet engine which is sometimes referred to as thermojet, a term now commonly used to describe a particular and completely unrelated pulsejet design.
Main components of Mikoyan-Gurevich I-250 motorjet-powered aircraft; the propeller is absent on some designs.
At the heart the motorjet is an ordinary piston engine (hence, the term motor), but instead of (or sometimes, as well as) driving a propeller, it drives a compressor. The compressed air is channeled into a combustion chamber, where fuel is injected and ignited. The high temperatures generated by the combustion cause the gases in the chamber to expand and escape at high velocity from the exhaust, creating a thermal reactive force that provides useful thrust.
Motorjet engines provide greater thrust than a propeller alone mounted on a piston engine; this has been successfully demonstrated in a number of different aircraft. A jet engine also can provide thrust at higher speeds where a propeller becomes less efficient or even ineffective; in fact, a jet engine gains efficiency as speed rises, while a propeller loses it (outside of a certain design range). This gives better efficiency in either operating range than an aircraft powered by just a propeller or a jet. The same is true of the dual-powerplant aircraft experimented with after the turbojet became practicable, which were equipped with both a piston-driven propeller and a turbojet engine.
Historyedit
In 1908 French inventor René Lorin proposed using a piston engine to compress air that would then be mixed with fuel and burned to produce pulses of hot gas that would be expelled through a nozzle to generate a propelling force.[1]
In 1917, O. Morize of Chateaudun, France, proposed the Morize ejector scheme in which a reciprocating engine drove a compressor supplying air to a liquid-fueled combustion chamber which discharged into a convergent-divergent tube and ultimately out into the atmosphere.
The term "motor jet" was established in a patent filed in Britain by J.H. Harris of Esher, U.K., in 1917.
It was next explored by Secondo Campini in the early 1930s, although it was not until 1940 that an aircraft, the Caproni Campini N.1 (sometimes referred to as C.C.2), would fly powered by his engine. Campini used the term thermojet at this time to describe his motorjet.
NACA engineer Eastman Jacobs was actively pursuing thermojet research in the early 1940s for a project that came to be known as Jake's jeep which was never completed as turbojet technology overtook it.[citation needed]
Japanese engineers developed the Tsu-11 motorjet engine to power Ohka aircraft as an alternative to the solid-fuel rocket engines that these aircraft were then using.
The SovietMikoyan-Gurevich I-250, designed in 1944, used a piston engine to drive both a propeller at the nose of the plane, and a Kholshchevnikov VRDK motorjet leading to a jet exhaust at the tail. Between 10 and 50 I-250 (a.k.a. MiG-13) aircraft were produced, serviced, and flown by the Soviet Navy through 1950. The similarly designed Sukhoi Su-5 was also produced as a prototype during the same period..
Motorjet research was nearly abandoned at the end of World War II as the turbojet was a more practical solution to jet power as it used the jet exhaust to drive a gas turbine, providing the power to drive the compressor without the additional weight of a piston engine that generated no thrust. One of the primary advantages of the motorjet layout was that the reciprocating engine provided power for the compressor and no turbine power section was needed. However, metallurgy and understanding of the design of turbines had advanced to a point after World War II where it was feasible to create a turbine to operate reliably in the high-velocity hot-gas environment downstream of the combustor, and the motorjet idea lost focus.
^Reithmaier, Larry (1994). Mach 1 and Beyond. McGraw-Hill Professional. p. 74. ISBN0-07-052021-6.
External linksedit
Nye Thermodynamics Thermojet
January 09, 2024
motorjet, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, january, 2009, le. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Motorjet news newspapers books scholar JSTOR January 2009 Learn how and when to remove this template message A motorjet is a rudimentary type of jet engine which is sometimes referred to as thermojet a term now commonly used to describe a particular and completely unrelated pulsejet design Main components of Mikoyan Gurevich I 250 motorjet powered aircraft the propeller is absent on some designs Contents 1 Design 2 History 3 See also 4 Notes 5 External linksDesign editAt the heart the motorjet is an ordinary piston engine hence the term motor but instead of or sometimes as well as driving a propeller it drives a compressor The compressed air is channeled into a combustion chamber where fuel is injected and ignited The high temperatures generated by the combustion cause the gases in the chamber to expand and escape at high velocity from the exhaust creating a thermal reactive force that provides useful thrust Motorjet engines provide greater thrust than a propeller alone mounted on a piston engine this has been successfully demonstrated in a number of different aircraft A jet engine also can provide thrust at higher speeds where a propeller becomes less efficient or even ineffective in fact a jet engine gains efficiency as speed rises while a propeller loses it outside of a certain design range This gives better efficiency in either operating range than an aircraft powered by just a propeller or a jet The same is true of the dual powerplant aircraft experimented with after the turbojet became practicable which were equipped with both a piston driven propeller and a turbojet engine History editIn 1908 French inventor Rene Lorin proposed using a piston engine to compress air that would then be mixed with fuel and burned to produce pulses of hot gas that would be expelled through a nozzle to generate a propelling force 1 In 1917 O Morize of Chateaudun France proposed the Morize ejector scheme in which a reciprocating engine drove a compressor supplying air to a liquid fueled combustion chamber which discharged into a convergent divergent tube and ultimately out into the atmosphere The term motor jet was established in a patent filed in Britain by J H Harris of Esher U K in 1917 It was next explored by Secondo Campini in the early 1930s although it was not until 1940 that an aircraft the Caproni Campini N 1 sometimes referred to as C C 2 would fly powered by his engine Campini used the term thermojet at this time to describe his motorjet NACA engineer Eastman Jacobs was actively pursuing thermojet research in the early 1940s for a project that came to be known as Jake s jeep which was never completed as turbojet technology overtook it citation needed Japanese engineers developed the Tsu 11 motorjet engine to power Ohka aircraft as an alternative to the solid fuel rocket engines that these aircraft were then using The Soviet Mikoyan Gurevich I 250 designed in 1944 used a piston engine to drive both a propeller at the nose of the plane and a Kholshchevnikov VRDK motorjet leading to a jet exhaust at the tail Between 10 and 50 I 250 a k a MiG 13 aircraft were produced serviced and flown by the Soviet Navy through 1950 The similarly designed Sukhoi Su 5 was also produced as a prototype during the same period Motorjet research was nearly abandoned at the end of World War II as the turbojet was a more practical solution to jet power as it used the jet exhaust to drive a gas turbine providing the power to drive the compressor without the additional weight of a piston engine that generated no thrust One of the primary advantages of the motorjet layout was that the reciprocating engine provided power for the compressor and no turbine power section was needed However metallurgy and understanding of the design of turbines had advanced to a point after World War II where it was feasible to create a turbine to operate reliably in the high velocity hot gas environment downstream of the combustor and the motorjet idea lost focus See also editLuigi Stipa Stipa CaproniNotes edit Reithmaier Larry 1994 Mach 1 and Beyond McGraw Hill Professional p 74 ISBN 0 07 052021 6 External links editA motorjet history and research webpage Nye Thermodynamics Thermojet Retrieved from https en wikipedia org w index php title Motorjet amp oldid 1182580132, wikipedia, wiki, book, books, library,
