Talk:Turbo-compound engine

Title
This title is grammatically incorrect, it should be Turbo-compounded engine, or perhaps turbo-compounding or even turbocompounding. Perhaps these should all be created and refer to one? — Preceding unsigned comment added by Jontw (talk • contribs) 14:59, 12 September 2007 (UTC)

Number of compound engine produced
"Today it's used on a few modern diesel engines" I don’t know the facts and figures but perhaps you need to look at the following link: http://www.scania.com/news/events/archive/2002/iaa_2002/ev_pr_11193.asp 15,000 is not a few to me for 2004. From 1994 to 1997 I believe Scania manufactured 1500 turbo-compounded engines however I am still trying to find my reference for this figure. Perhaps an article on Scania with a section on their turbo-compounded engines with a cross reference from here. There is very little information on the public domain for the turbocompounded Volvo engine, more information on these engines would be much appreciated. — Preceding unsigned comment added by Jontw (talk • contribs) 15:39, 12 September 2007 (UTC)

Exhaust gas restriction
One part of the article claims that a power turbine does not impact exhaust gas flow since it is a velocity turbine, not a pressure turbine. To me, this does not make sense. I would be inclined to agree if the turbine was free-wheeling, in which case it wouldn't be producing any power. The turbine is geared directly onto the crankshaft. It seems to me that this speed-synchronizing (yes, I know they're geared up, I'm not an idiot) will cause the speed of the turbine to not match the output of exhaust gases from the engine as engine load increases, resulting in immense backpressure. (and, of course, immense torque on the turbine, which is then transferred to the engine's shaft)


 * 'Actually, using this turbine caused a boost in back pressure thereby the operating temperature in the cylinder, which include the responsible factors pertaining to high wear inside engine and their failure.'

Makes sense to me. This isn't however a very reliable source, so I can't add it to the article.

Turbo-compounding fascinates me, but there isn't a lot of info about it out there. --Joffeloff (talk) 13:37, 14 January 2012 (UTC)
 * The image of Nomad 2 motor shows the change with a clutch so that the turbine supplies power only when it is moving faster than the crankshaft. In Formula 1 motors the MGU-H operates by switching the exhaust powered turbine to a generator (rather than increasing compression in cylinders). It also keeps the compression fan "spooled up" (spinning at high speed) for rapid engagement with compressor (no "turbo lag") though since it's free spinning and not creating pressure it requires less force, with any residual generated electricity going to the main battery. This would require a very high speed electric motor (120,000 rpm) connected to the turbo shaft and I assume it is the generator being supplied power (working both ways) since images show no additional motor. It is also said that Mercedes (and perhaps Ferrari now, too (2017)) are using a venturi effect opening in the exhaust to increase airflow along with the exhaust gases to maximize generated power. I still find it misleading to call it a scavenging of heat energy in that it really operates with the pressure of the flowing gases (and air mix). Yes, this initiates due to the exhaust gases being hot (increasing pressure) but does not directly convert heat; more pressurized gas scavenging. But that is still more efficient than any thermopile/TEG (thermoelectric generator) that have only reached 15% efficiency in the best of cases and require additional cooling complexity. https://www.motorsport.com/all/photo/main-gallery/mgu-h-9667182/?a=791187
 * Whinestein (talk) 10:18, 20 October 2017 (UTC)

most of the footnote links are dead
I tried the majority of links (Oct 2017) and they are dead, defaulting to website index page. No current equivalent pages did I find (general dumbing down of internet sites, losing information because of cost of remapping when giving a facelift or new template to site, having much less qualified web design people these days, making the entire site "mobile friendly" without links to legacy site or pages). Whinestein (talk) 10:25, 20 October 2017 (UTC)