Paquitotrek
Paquitotrek (talk) 23:13, 16 May 2010 (UTC)
Turbina
editA los gases calientes que salen del combustor se les permite expandirse a lo largo de la turbina. Usualmente las turbinas se construyen con metales para altas temperaturas tales como el inconel para resistirlas, algunas veces las turbinas cuentan con canales de enfriamiento internos.
En su primera etapa, la turbina es mayormente una turbina de impulso (similar a una turbina Pelton) y su rotación se debe al impacto de la corriente caliente de gas. Las etapas siguientes constan de ductos convergentes que aceleran el gas hacia atrás y obtener energía de ese proceso. Caídas de presión y energía se transfieren a la flecha o eje de la máquina. La energía rotacional se utiliza principalmente para impulsar el compresor. Una parte de la potencia de la flecha se extrae para impulsar otros accesorios tales como las bombas del combustible, aceite e hidráulica. Dado que la temperatura de entrada de los gases a la turbina es muy alta, la relación de presiones en la turbina es mucho menor que ésta en el compresor. En un turbojet casi 65% de la potencia generada mediante la quema de combustible la utiliza el compresor para comprimir el aire que el turbojet utiliza.[citation needed]
Luego de la turbina, se permite a los gases expandirse a través del la tobera de gases exhaustos a presión atmosférica, así se produce un jet de alta velocidad en el efluente de gases exhaustos. En una tobera convergente, los ductos se estrechan progresivamente hasta la garganta. La relación de presión en la tobera de un turbojet usualmente es suficientemente alta para que los gases que se expanden alcancen Mach 1.0 y se provoque un ahogamiento en la tobera. Normalmente, el flujo será supersónico en el efluente de gases exhaustos fuera de la máquina.
Si se utiliza una tobera convergente-divergente De Laval, la sección divergente (área de sección transversal incremental) permite que los gases alcancen velocidades supersónicas en la tobera misma. Esto es ligeramente más eficiente en términos de empuje que utilizar una tobera convergente. Sin embargo lo anterior añade complejidad y peso al sistema dado que la tobera convergente-divergente debe ser completamente variable en su forma para lidiar con cambios en el flujo de gas causados por el ahogamiento de la máquina.
Titanium aluminide, TiAl, is an intermetallic chemical compound. It is lightweight and resistant to oxidation and heat, however it suffers from low ductility. The density of gamma TiAl is about 4.0 g/cm³. It finds use in several applications including automobiles and aircraft. The development of TiAl based alloys began about 1970; however the alloys have only been used in these applications since about 2000.
Titanium aluminide has three major intermetallic compounds: gamma TiAl, alpha 2-Ti3Al and TiAl3. Among the three, gamma TiAl has received the most interest and applications. Gamma TiAl has excellent mechanical properties and oxidation and corrosion resistance at elevated temperatures (over 600 degrees Celsius), which makes it a possible replacement for traditional Ni based superalloy components in aircraft turbine engines.
TiAl based alloys have a strong potential to increase the thrust-to-weight ratio in the aircraft engine. This is especially the case with the engine's low pressure turbine blades and the high pressure compressor blades. These are traditionally made up of Ni based superalloy, which is nearly twice as dense as TiAl based alloys.
General Electric has recently announced that gamma TiAl low pressure turbine blades will be used on its GEnx engine, which powers the Boeing 787 and Boeing 747-8 aircraft. This is the first large-scale use of this material on a commercial jet engine. The TiAl LPT blades are cast by Precision Castparts Corp. and Avio s.p.a.
External links
edit- Titanium Aluminide Applications in the HighSpeed Civil Transport
- Titanium Aluminides - Intermetallics on azom.com.
- Power House (GEnx TiAl LPT Blade Announcement)
- Edward A. Loria (2001). "Quo vadis gamma titanium aluminide". Intermetallics. 9 (12): 997–1001. doi:10.1016/S0966-9795(01)00064-4.
- Donachie, Matthew J (2000). Titanium: a technical guide. p. 131. ISBN 9780871706867.
- Kassner, Michael E; P�rez-Prado, María-Teresa (2004). Fundamentals of creep in metals and alloys. p. 175. ISBN 9780080436371.
{{cite book}}: replacement character in|author2=at position 2 (help)
Category:Aluminides Category:Titanium alloys Category:Intermetallics
Your submission at Articles for creation: Julio López Chávez (March 4)
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Hello, Paquitotrek!
Having an article declined at Articles for Creation can be disappointing. If you are wondering why your article submission was declined, please post a question at the Articles for creation help desk. If you have any other questions about your editing experience, we'd love to help you at the Teahouse, a friendly space on Wikipedia where experienced editors lend a hand to help new editors like yourself! See you there! J947 (c), at 02:59, 4 March 2020 (UTC)
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Draft:Julio López Chávez concern
editHi there, I'm MDanielsBot. I just wanted to let you know that Draft:Julio López Chávez, a page you created, has not been edited in 5 months. The Articles for Creation space is not an indefinite storage location for content that is not appropriate for articlespace.
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Thank you for your attention. MDanielsBot (talk) 02:50, 7 August 2020 (UTC)
Draft:Julio López Chávez concern
editHi there, I'm MDanielsBot. I just wanted to let you know that Draft:Julio López Chávez, a page you created, has not been edited in 5 months. The Articles for Creation space is not an indefinite storage location for content that is not appropriate for articlespace.
If your submission is not edited soon, it could be nominated for deletion. If you would like to attempt to save it, you will need to improve it.
You may request Userfication of the content if it meets requirements.
If the deletion has already occured, instructions on how you may be able to retrieve it are available at WP:REFUND/G13.
Thank you for your attention. MDanielsBot (talk) 02:08, 10 August 2020 (UTC)
Your draft article, Draft:Julio López Chávez
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Hello, Paquitotrek. It has been over six months since you last edited the Articles for Creation submission or Draft page you started, "Julio López Chávez".
In accordance with our policy that Wikipedia is not for the indefinite hosting of material deemed unsuitable for the encyclopedia mainspace, the draft has been deleted. If you plan on working on it further and you wish to retrieve it, you can request its undeletion by following the instructions at this link. An administrator will, in most cases, restore the submission so you can continue to work on it.
Thanks for your submission to Wikipedia, and happy editing. Liz Read! Talk! 19:48, 4 September 2020 (UTC)