The MAN M-System, also referred to as M-Process and M combustion process, is a direct injection system for Diesel engines. In M-System engines, the fuel is injected onto the walls of the combustion chamber that is solely located inside the piston, and shaped like a sphere. The M-System was rendered obsolete by modern fuel injection systems for Diesel engines. Due to its particularities, the M-System was only used for stationary applications and commercial vehicle engines, passenger car engines with this design have never been made. The letter M is an abbreviation for the German word Mittenkugelverfahren,[1] meaning centre sphere combustion process.
M-System engine with its cylinder head removed. Note the piston with the characteristic sphere-shaped combustion chamber. (4 VD 14,5/12-1 SRW)
Unlike regular Diesel engines, in which the fuel is injected as far away as possible from the combustion chamber walls to obtain better efficiency, in M-System engines, the fuel is injected onto the walls of the combustion chamber. The combustion chamber is located inside the piston bowl and shaped like a sphere. Usually, M-System engines have single-spray or twin-spray injectors. In combination with the relatively low injection pressure, this results in a fine fuel film on the combustion chamber walls. However, a small portion of the fuel is injected into the air to initiate combustion, which raises the temperature inside the cylinder. The elevated temperature then causes the fuel film to vaporise and combust. Regular Diesel engines mix air and fuel during injection by creating a high fuel velocity with high injection pressure. In M-System engines however, mixing air and fuel takes place after injection. Due to the low velocity of the fuel vaporising from the combustion chamber walls, the air velocity has to be great to achieve a high relative air-fuel velocity to aid mixing. Therefore, M-System engines have special whirl intake ports.[2]
The idea of this operating principle is creating an air-fuel mixture that is more homogeneous with a dispersion of air and fuel that is more even than in regular Diesel engines. Thus, M-System engines have relatively good air utilisation and can operate under heavy load without sooting. Due to the low amount of fuel that is mixed with air as ignition begins, the increase in pressure is fairly low, resulting in low combustion noise.[2]
M-System engines suffer from high heat-transfer and flow losses, resulting in reduced efficiency and therefore higher fuel consumption. Furthermore, the thermal loads of both piston and cylinder head are very high, making M-System engines not very suitable for turbocharging. Under medium load, M-System engines emit high levels of hydrocarbons.[2]
Multifuel operation
In M-System engines, the fuel is not exposed to heat during the injection phase, which not only allows using regular Diesel engine fuels, but also petroleum fractions with average boiling points reaching from 313 to 673 K as well as petrol with no more than 86 RON as fuels.[3]
A special iteration of the M-System, the FM-System, was designed to further improve the M-System's multifuel characteristics. FM is an abbreviation for the German word Fremdzündungsmittenkugelverfahren, meaning spark ignition centre sphere combustion process. FM-System engines feature spark ignition, but still keep characteristics that are typical of Diesel engines, such as internal mixture formation and quality torque control. Therefore, FM engines are neither Diesel, nor Otto engines; instead, they operate on a hybrid combustion process. Compared to regular M-System engines, the exhaust behaviour is better.[2] The spark plugs used for FM-System engines are located at the opposite side of the injection nozzle and usually have two parallel pin electrodes, or three mass electrodes.[4]
German engineer Kurt Blume is said to have had the idea of the M-System in 1940. In 1941, he first brought his idea to paper.[3] After World War II, J. Siegfried Meurer, then an MAN engineer, continued development of the M-System and prepared it for series production.[5] Meurer obtained a patent (DBP 865683) on the M-System in 1951.[6] First prototype M-System engines ran on the test bench in 1954 and 1955.[7]East German manufacturer IFA acquired a licence for the M-System and built the 4 VD 14,5/12-1 SRW Diesel engine starting from 1967, which is the engine with the highest production number featuring the M-System.[8] In the mid 1960s, J. Böttger claimed that MAN M-engines did not operate on the principle described in Meurer's patent (DBP 865683), which resulted in a patent lawsuit.[9] FM-System engines have been used from the late-1960s to the mid-1980s.[4]
References
^Olaf von Fersen (ed.): Ein Jahrhundert Automobiltechnik: Personenwagen, Springer, Düsseldorf 1986, ISBN978-3-642-95773-4. p. 279
^ abcdRichard van Basshuysen, Fred Schäfer (ed.): Handbuch Verbrennungsmotor: Grundlagen, Komponenten, Systeme, Perspektiven, 8th edition, Springer, Wiesbaden 2017. ISBN978-3-658-10902-8. Chaptep 15.1, p. 761
^ abHans Christian Graf von Seherr-Thoß (auth.): Die Technik des MAN Nutzfahrzeugbaus in: Nutzfahrzeuge AG (ed.): Leistung und Weg: Zur Geschichte des MAN Nutzfahrzeugbaus, Springer, Berlin/Heidelberg 1991. ISBN978-3-642-93490-2. p. 438
^ abRichard van Basshuysen (ed.): Ottomotor mit Direkteinspritzung und Direkteinblasung: Ottokraftstoffe, Erdgas, Methan, Wasserstoff, 4th edition, Springer, Wiesbaden 2017. ISBN9783658122157. p. 23–24
^Achim Gaier: Nutzfahrzeuge in der DDR, Band 2. 2nd edition, Schrader, Stuttgart 2002. ISBN9783613872103. p. 100
^Hans Christian Graf von Seherr-Thoß (auth.): Die Technik des MAN Nutzfahrzeugbaus, in MAN Nutzfahrzeuge AG (ed.): Leistung und Weg: Zur Geschichte des MAN Nutzfahrzeugbaus, Springer, Berlin/Heidelberg 1991. ISBN978-3-642-93490-2. p. 465.
^ATZ, Automobiltechnische Zeitschrift, Volume 75, 1973. p. 152
^Peter Kirchberg: Plaste, Blech und Planwirtschaft: die Geschichte des Automobilbaus in der DDR, 2nd edition, Nicolai, Berlin 2001. ISBN978-3-87584-027-8. p. 757
^Kammer der Technik (ed.): Zum Patentstreit über das M.A.N.-M-Verfahren, in Kraftfahrzeugtechnik, 05/1965, page 164
January 07, 2023
system, also, referred, process, combustion, process, direct, injection, system, diesel, engines, engines, fuel, injected, onto, walls, combustion, chamber, that, solely, located, inside, piston, shaped, like, sphere, rendered, obsolete, modern, fuel, injectio. The MAN M System also referred to as M Process and M combustion process is a direct injection system for Diesel engines In M System engines the fuel is injected onto the walls of the combustion chamber that is solely located inside the piston and shaped like a sphere The M System was rendered obsolete by modern fuel injection systems for Diesel engines Due to its particularities the M System was only used for stationary applications and commercial vehicle engines passenger car engines with this design have never been made The letter M is an abbreviation for the German word Mittenkugelverfahren 1 meaning centre sphere combustion process M System engine with its cylinder head removed Note the piston with the characteristic sphere shaped combustion chamber 4 VD 14 5 12 1 SRW Contents 1 Operating principle 2 Multifuel operation 3 History 4 ReferencesOperating principle Edit Schematic Unlike regular Diesel engines in which the fuel is injected as far away as possible from the combustion chamber walls to obtain better efficiency in M System engines the fuel is injected onto the walls of the combustion chamber The combustion chamber is located inside the piston bowl and shaped like a sphere Usually M System engines have single spray or twin spray injectors In combination with the relatively low injection pressure this results in a fine fuel film on the combustion chamber walls However a small portion of the fuel is injected into the air to initiate combustion which raises the temperature inside the cylinder The elevated temperature then causes the fuel film to vaporise and combust Regular Diesel engines mix air and fuel during injection by creating a high fuel velocity with high injection pressure In M System engines however mixing air and fuel takes place after injection Due to the low velocity of the fuel vaporising from the combustion chamber walls the air velocity has to be great to achieve a high relative air fuel velocity to aid mixing Therefore M System engines have special whirl intake ports 2 The idea of this operating principle is creating an air fuel mixture that is more homogeneous with a dispersion of air and fuel that is more even than in regular Diesel engines Thus M System engines have relatively good air utilisation and can operate under heavy load without sooting Due to the low amount of fuel that is mixed with air as ignition begins the increase in pressure is fairly low resulting in low combustion noise 2 M System engines suffer from high heat transfer and flow losses resulting in reduced efficiency and therefore higher fuel consumption Furthermore the thermal loads of both piston and cylinder head are very high making M System engines not very suitable for turbocharging Under medium load M System engines emit high levels of hydrocarbons 2 Multifuel operation EditIn M System engines the fuel is not exposed to heat during the injection phase which not only allows using regular Diesel engine fuels but also petroleum fractions with average boiling points reaching from 313 to 673 K as well as petrol with no more than 86 RON as fuels 3 A special iteration of the M System the FM System was designed to further improve the M System s multifuel characteristics FM is an abbreviation for the German word Fremdzundungsmittenkugelverfahren meaning spark ignition centre sphere combustion process FM System engines feature spark ignition but still keep characteristics that are typical of Diesel engines such as internal mixture formation and quality torque control Therefore FM engines are neither Diesel nor Otto engines instead they operate on a hybrid combustion process Compared to regular M System engines the exhaust behaviour is better 2 The spark plugs used for FM System engines are located at the opposite side of the injection nozzle and usually have two parallel pin electrodes or three mass electrodes 4 History Edit IFA W50 a lorry with an M System engine German engineer Kurt Blume is said to have had the idea of the M System in 1940 In 1941 he first brought his idea to paper 3 After World War II J Siegfried Meurer then an MAN engineer continued development of the M System and prepared it for series production 5 Meurer obtained a patent DBP 865683 on the M System in 1951 6 First prototype M System engines ran on the test bench in 1954 and 1955 7 East German manufacturer IFA acquired a licence for the M System and built the 4 VD 14 5 12 1 SRW Diesel engine starting from 1967 which is the engine with the highest production number featuring the M System 8 In the mid 1960s J Bottger claimed that MAN M engines did not operate on the principle described in Meurer s patent DBP 865683 which resulted in a patent lawsuit 9 FM System engines have been used from the late 1960s to the mid 1980s 4 References Edit Olaf von Fersen ed Ein Jahrhundert Automobiltechnik Personenwagen Springer Dusseldorf 1986 ISBN 978 3 642 95773 4 p 279 a b c d Richard van Basshuysen Fred Schafer ed Handbuch Verbrennungsmotor Grundlagen Komponenten Systeme Perspektiven 8th edition Springer Wiesbaden 2017 ISBN 978 3 658 10902 8 Chaptep 15 1 p 761 a b Hans Christian Graf von Seherr Thoss auth Die Technik des MAN Nutzfahrzeugbaus in Nutzfahrzeuge AG ed Leistung und Weg Zur Geschichte des MAN Nutzfahrzeugbaus Springer Berlin Heidelberg 1991 ISBN 978 3 642 93490 2 p 438 a b Richard van Basshuysen ed Ottomotor mit Direkteinspritzung und Direkteinblasung Ottokraftstoffe Erdgas Methan Wasserstoff 4th edition Springer Wiesbaden 2017 ISBN 9783658122157 p 23 24 Achim Gaier Nutzfahrzeuge in der DDR Band 2 2nd edition Schrader Stuttgart 2002 ISBN 9783613872103 p 100 Hans Christian Graf von Seherr Thoss auth Die Technik des MAN Nutzfahrzeugbaus in MAN Nutzfahrzeuge AG ed Leistung und Weg Zur Geschichte des MAN Nutzfahrzeugbaus Springer Berlin Heidelberg 1991 ISBN 978 3 642 93490 2 p 465 ATZ Automobiltechnische Zeitschrift Volume 75 1973 p 152 Peter Kirchberg Plaste Blech und Planwirtschaft die Geschichte des Automobilbaus in der DDR 2nd edition Nicolai Berlin 2001 ISBN 978 3 87584 027 8 p 757 Kammer der Technik ed Zum Patentstreit uber das M A N M Verfahren in Kraftfahrzeugtechnik 05 1965 page 164 Retrieved from https en wikipedia org w index php title M System amp oldid 1129638049, wikipedia, wiki, book, books, library,
