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#11
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Seems like 6 of one, 1/2 dozen of another?
Dan wrote:
BobR wrote: On Aug 28, 3:13 am, Oliver Arend wrote: Regardless of what is fact and what is fiction, most of what has been said about composite canard pushers vs. metal classic tractors is comparing apples to oranges (IIRC, in Germany we usually compare apples to pears). Advantages and disadvantes have been pointed out, but do not relate to the original pusher-vs.-tractor question. The Cessna Skymaster example in the original text suits it much better. Apart from the problem of aft CG and hence the difficulty to make a single-engine pusher in a classical wing layout, there are two opposing factors: 1. The tractor engine works more efficiently since the prop is in an undisturbed air stream. The slipstream may be able to increase maximum lift on parts of the wing, but can induce a rolling moment. The turbulence created creates more drag, especially on the fuselage. Also, putting the engine up front makes it less likely to have an aerodynamically optimized fuselage. 2. The pusher engine works less efficiently since the prop sits in an airstream that has already passed fuselage and wing. OTOH, the fuselage can be shape-optimized more easily and sees an undisturbed, laminar airflow. Maximum lift is likely to be a little lower. Now, which of these effects is the dominant one? Also, if you have a twin engine airplane, the fuselage is out of the equation, so the final result may be different!? Oliver So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot |
#12
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Seems like 6 of one, 1/2 dozen of another?
Jerry Wass wrote:
Dan wrote: BobR wrote: On Aug 28, 3:13 am, Oliver Arend wrote: Regardless of what is fact and what is fiction, most of what has been said about composite canard pushers vs. metal classic tractors is comparing apples to oranges (IIRC, in Germany we usually compare apples to pears). Advantages and disadvantes have been pointed out, but do not relate to the original pusher-vs.-tractor question. The Cessna Skymaster example in the original text suits it much better. Apart from the problem of aft CG and hence the difficulty to make a single-engine pusher in a classical wing layout, there are two opposing factors: 1. The tractor engine works more efficiently since the prop is in an undisturbed air stream. The slipstream may be able to increase maximum lift on parts of the wing, but can induce a rolling moment. The turbulence created creates more drag, especially on the fuselage. Also, putting the engine up front makes it less likely to have an aerodynamically optimized fuselage. 2. The pusher engine works less efficiently since the prop sits in an airstream that has already passed fuselage and wing. OTOH, the fuselage can be shape-optimized more easily and sees an undisturbed, laminar airflow. Maximum lift is likely to be a little lower. Now, which of these effects is the dominant one? Also, if you have a twin engine airplane, the fuselage is out of the equation, so the final result may be different!? Oliver So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven? |
#13
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Seems like 6 of one, 1/2 dozen of another?
On Aug 28, 2:36*pm, cavelamb wrote:
Jerry Wass wrote: Dan wrote: BobR wrote: On Aug 28, 3:13 am, Oliver Arend wrote: Regardless of what is fact and what is fiction, most of what has been said about composite canard pushers vs. metal classic tractors is comparing apples to oranges (IIRC, in Germany we usually compare apples to pears). Advantages and disadvantes have been pointed out, but do not relate to the original pusher-vs.-tractor question. The Cessna Skymaster example in the original text suits it much better. Apart from the problem of aft CG and hence the difficulty to make a single-engine pusher in a classical wing layout, there are two opposing factors: 1. The tractor engine works more efficiently since the prop is in an undisturbed air stream. The slipstream may be able to increase maximum lift on parts of the wing, but can induce a rolling moment. The turbulence created creates more drag, especially on the fuselage. Also, putting the engine up front makes it less likely to have an aerodynamically optimized fuselage. 2. The pusher engine works less efficiently since the prop sits in an airstream that has already passed fuselage and wing. OTOH, the fuselage can be shape-optimized more easily and sees an undisturbed, laminar airflow. Maximum lift is likely to be a little lower. Now, which of these effects is the dominant one? Also, if you have a twin engine airplane, the fuselage is out of the equation, so the final result may be different!? Oliver So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. * On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven?- Hide quoted text - There you go again using that educated government math. |
#14
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Seems like 6 of one, 1/2 dozen of another?
BobR wrote:
On Aug 28, 2:36 pm, cavelamb wrote: Jerry Wass wrote: Dan wrote: BobR wrote: On Aug 28, 3:13 am, Oliver Arend wrote: Regardless of what is fact and what is fiction, most of what has been said about composite canard pushers vs. metal classic tractors is comparing apples to oranges (IIRC, in Germany we usually compare apples to pears). Advantages and disadvantes have been pointed out, but do not relate to the original pusher-vs.-tractor question. The Cessna Skymaster example in the original text suits it much better. Apart from the problem of aft CG and hence the difficulty to make a single-engine pusher in a classical wing layout, there are two opposing factors: 1. The tractor engine works more efficiently since the prop is in an undisturbed air stream. The slipstream may be able to increase maximum lift on parts of the wing, but can induce a rolling moment. The turbulence created creates more drag, especially on the fuselage. Also, putting the engine up front makes it less likely to have an aerodynamically optimized fuselage. 2. The pusher engine works less efficiently since the prop sits in an airstream that has already passed fuselage and wing. OTOH, the fuselage can be shape-optimized more easily and sees an undisturbed, laminar airflow. Maximum lift is likely to be a little lower. Now, which of these effects is the dominant one? Also, if you have a twin engine airplane, the fuselage is out of the equation, so the final result may be different!? Oliver So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven?- Hide quoted text - There you go again using that educated government math. It could be worse, he could be using algebra. That's when you stop counting on your fingers and start using your toes. Higher level math usually requires illegal substances. Dan, U.S. Air Force, retired |
#15
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Seems like 6 of one, 1/2 dozen of another?
On Aug 28, 3:36*pm, cavelamb wrote:
Jerry Wass wrote: Dan wrote: BobR wrote: On Aug 28, 3:13 am, Oliver Arend wrote: Regardless of what is fact and what is fiction, most of what has been said about composite canard pushers vs. metal classic tractors is comparing apples to oranges (IIRC, in Germany we usually compare apples to pears). Advantages and disadvantes have been pointed out, but do not relate to the original pusher-vs.-tractor question. The Cessna Skymaster example in the original text suits it much better. Apart from the problem of aft CG and hence the difficulty to make a single-engine pusher in a classical wing layout, there are two opposing factors: 1. The tractor engine works more efficiently since the prop is in an undisturbed air stream. The slipstream may be able to increase maximum lift on parts of the wing, but can induce a rolling moment. The turbulence created creates more drag, especially on the fuselage. Also, putting the engine up front makes it less likely to have an aerodynamically optimized fuselage. 2. The pusher engine works less efficiently since the prop sits in an airstream that has already passed fuselage and wing. OTOH, the fuselage can be shape-optimized more easily and sees an undisturbed, laminar airflow. Maximum lift is likely to be a little lower. Now, which of these effects is the dominant one? Also, if you have a twin engine airplane, the fuselage is out of the equation, so the final result may be different!? Oliver So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. * On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven?- Hide quoted text - - Show quoted text - When you put your plane in reverse do the backup lights come on? |
#16
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Seems like 6 of one, 1/2 dozen of another?
In article
, Mark wrote: On Aug 28, 3:36*pm, cavelamb wrote: Jerry Wass wrote: Dan wrote: BobR wrote: So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. * On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven?- Hide quoted text - When you put your plane in reverse do the backup lights come on? Watched an MU-2 backing into a parking spot at Rawlings, WY years ago. I wondered about it then. Once I'd picked up my teeth from the ramp. |
#17
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Seems like 6 of one, 1/2 dozen of another?
"Steve Hix" wrote in message
... In article , Mark wrote: On Aug 28, 3:36 pm, cavelamb wrote: Jerry Wass wrote: Dan wrote: BobR wrote: So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven?- Hide quoted text - When you put your plane in reverse do the backup lights come on? Watched an MU-2 backing into a parking spot at Rawlings, WY years ago. I wondered about it then. Once I'd picked up my teeth from the ramp. It looks just as strange to see a Cessna Caravan do it. |
#18
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Seems like 6 of one, 1/2 dozen of another?
"Peter Dohm" wrote in message ... "Steve Hix" wrote in message ... In article , Mark wrote: On Aug 28, 3:36 pm, cavelamb wrote: Jerry Wass wrote: Dan wrote: BobR wrote: So let me sum it up thusly.... 6 of one, 1/2 dozen of the other. On the other hand..... there are more fingers. Dan, U.S. Air Force, retired Are we speaking of 6 fingered hands??--that would broaden the subject sumwhot starting from ten on this hand we have - 10, 9, 8, 7, and 6. Plus five on the other hand would be = eleven?- Hide quoted text - When you put your plane in reverse do the backup lights come on? Watched an MU-2 backing into a parking spot at Rawlings, WY years ago. I wondered about it then. Once I'd picked up my teeth from the ramp. It looks just as strange to see a Cessna Caravan do it. Or a turbo Thrush G -- A man is known by the company he keeps- Unknown Anyolmouse |
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