Edwest wrote:
A good book about the development of propellers.
I would say a "not so good book about the development of propellers". It shows a remarkable chauvinistic approach to this technology, centering it`s development in the US and neglecting european achievements. Per example, the Soviet Union`s work in this technology is completelly absent from this book.
I`m Still waiting for a good book about the development of propellers! Soviet developments would be most welcome.
Edwest wrote:
A good book about the development of propellers.
I would say a "not so good book about the development of propellers". It shows a remarkable chauvinistic approach to this technology, centering it`s development in the US and neglecting european achievements. Per example, the Soviet Union`s work in this technology is completelly absent from this book.
I`m Still waiting for a good book about the development of propellers! Soviet developments would be most welcome.
I am not totally disagreeing with your broader conclusions that the book has very little on German developments, but I would be a bit cautions about saying its not "A" good book on propellors.
I was at the Aircraft Engine Historical Society convention meeting in Dayton Ohio in person when the author Jeremy Kinney came and made us a presentation on his book. He freely admitted he had not had the time and money to make a huge trip and research effort to look into German developments, but I dont think this makes the rest of his book "void".
With my own book comig out soon, I really dont think people appreciate how hard it is to write some sort of "definitive global complete" history of any topic if you plan to actually use proper primary sources. I must have spent... I dont know... maybe... £25,000 and 5 years researching my book, and I had to give up on Japan and Russia because its simply financially and logistically impossible. Not to mention nobody will publish a 1000page treatise these days. If you write one, its commercially unviable.
I spent several months making contacts in Russia to try to research it, and I would have needed at least £8000 and six months to have made a serious effort to do so, before you even add in the cost of a translator/guide/fixer which you need to go to places like that.
I`m not making excuses for poor research,or poor conclusions or willful ignorance,but its a very useful book and whilst another is required to complete the story, I personally recommend anyone interested in propellors buys it.
The synchronization is one logical aspect, but also the German preference for shooting straight through the propeller hub. The German 3 blade propeller hub of the BF109 looks allready quite large, this is surly due to the fact, that the hub was designed to offer enough space for shooting through it. With four blades, there might have been the necessity to increase the diameter and the weight of the hub even moreRegarding contra-props, personally I think that for single-engined installations the greatest improvement comes from the vastly improved handling. Just read the Spitfire test report comparing contra-prop and single-rotation variants, there is huge difference in handling. With the contra-rotating propeller especially directional trimming changes were reduced to near nil. And it also allowed the use of full-power on take-off. Look at the take-off performance of a restored Mk. XIX Spit retrofitted with a contra-prop.
Personally I find the synchronization theory a very plausible for German devotion to 3-bladers.
Or the German engineers accepted much greater blade chords (and higher loads on pitch change mechanisms), greater tip speeds, or poorer performance in some conditions due to insufficient blade areaSurely one of the most significant factors in practice is ground clearance as determined by undercarriage design. The F4U Corsair has a 3 blade large diameter prop because it has the legs from day one. The Spitfire didn't have the clearance, so more blades were the way forward.
From all this I'm inferring that the German planes had taller undercarriage.