There is another benefit of these propellers, is the sound they make which is really awesome such examples of beautiful sound contrarotating planes which are built by Russian (TU95 and AN22)
Yes, it does increase engine efficiency by converting the helical or spiral thrust by adding another set of propeller from behind, in opposing direction it creates straight slipstream and adding lower power ratio to more thrust ratio. The disadvantage is the noise and the complexity of the assembly.
I have also noticed ships / boats using contra-rotating props. Whilst I admit to knowing nothing about boat, I’d say you can only steer with the use of a rudder.
Contra-rotating boat and ship propellers reduce their 'handedness'. Boats/ships, especially in reverse and varying by rudder setup, can creep to the port or starboard due to the rotation of her propeller. Theoretically a contra-rotating propeller fixes that issue, but I believe it has more to do with efficiency.
It does increase the efficiency by roughly 6-16% however sometimes the mschanical complexity and the wait of the added gears can cancel out its efficiency.
There is this contra-rotating propfan concept (An-70) that seems to be very efficient and quiet, also allowing for turbofan-like speeds. Any ideas on what's happening there?
It has different blade counts for the front snd back rotord and possibly dofferent blade shape and speed but were not sure on that. That drastically reduces noise
There is another benefit of these propellers, is the sound they make which is really awesome such examples of beautiful sound contrarotating planes which are built by Russian (TU95 and AN22)
but the sound up close is deafening
ka 50. wyvern
On the Russian TU144 the tips of the contra rotating propellor blades go supersonic, which makes the sound extremely loud
This is all well and good, but I'm looking for the mechanical, how it works explanation and you don't cover that at all. To bad.
Check out the ysterplaat shackelton on the rebuild of the gearbox, may help
What about thrust. More or less with given power input?
Very Nice Thanks
Was just wondering, can they used as pushers on an aircraft ?
This might help. www.flickr.com/photos/ruthann/432027081/
Does this increase efficiency of the engines? What % more thrust is gained if any?
Yes, it does increase engine efficiency by converting the helical or spiral thrust by adding another set of propeller from behind, in opposing direction it creates straight slipstream and adding lower power ratio to more thrust ratio. The disadvantage is the noise and the complexity of the assembly.
should be from 6% to 16 %
Thanks Roddy, some ships and power boats are having this setup , can contra props steer the boat straight without using rudder in still water ?
I have also noticed ships / boats using contra-rotating props. Whilst I admit to knowing nothing about boat, I’d say you can only steer with the use of a rudder.
Contra-rotating boat and ship propellers reduce their 'handedness'. Boats/ships, especially in reverse and varying by rudder setup, can creep to the port or starboard due to the rotation of her propeller. Theoretically a contra-rotating propeller fixes that issue, but I believe it has more to do with efficiency.
Thanks Roddy and Evan, so in theory slight corrections are made with min effective rudder angle yeah
What about thrust?
It doesnt improve thrust but it does prodyce energy from what wouldve been lost with a single propeller
Why do you say kilowatts
what about efficiency?
It does increase the efficiency by roughly 6-16% however sometimes the mschanical complexity and the wait of the added gears can cancel out its efficiency.
Found this video trying to figure out if Ripslinger's props were based in reality 😂
Ye
If the content creator is watching this, you have no idea of how I am applying the physics in the video to a context situation
KW is hydro not horsepower the latter is the right way to say it
great video....
There is this contra-rotating propfan concept (An-70) that seems to be very efficient and quiet, also allowing for turbofan-like speeds. Any ideas on what's happening there?
It has different blade counts for the front snd back rotord and possibly dofferent blade shape and speed but were not sure on that. That drastically reduces noise
Thanks! Very interesting.
Nice
Russian AN-22 giant aircraft has the contra rotating propellers, i don't think so that it has a disadvantage effects.