Results 1 to 10 of 114

Thread: ROLLS-ROYCE CRECY

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #21
    Join Date
    Feb 2004
    Location
    Mtn. View, Calif.
    Posts
    2,111

    Default Re: ROLLS-ROYCE CRECY

    I understand the venturi principle clearly, and I see what the drawings are representing.

    What I don't see is some form of evidence that this would be more efficient than a standard 2 or 3 blade windmill.


    Resistance of the wind to flow into and through the venturi rather than around it, and the drag of the walls within the long tapered tube will make it less efficient. Further resistance/drag will result from the air being drawn through that long"tube" from the generator turbine to the venturi device.


    Also, the smaller diameter generator turbine fan won't be nearly as efficient as a modern windmill propeller, whose blades aren't all that dis-similar to that in form (long span, short chord) and materials) carbon fiber) of a very efficient thermal competition glider. I'm sure technology learned by the wings of the latter has gone into the former.


    What makes the venturi "windmill" superior? I can see that it would be safer for predatory birds, many of which are dying from being struck while hunting around windmill farms, but I don't think it would be more efficient than a modern 'mill.


    Just my thoughts. I'm not trying to offend anyone. Have anyone tried placing a large venturi out in the open breezes and measured the results yet under real world conditions?


    .



    I don't know about the RAMJET-IN-A-VENTURI idea either. Sure, the airflow at the narrowest point is increased in velocity, but there's also that significant drop in pressure, negating any benefits of the former for the internally mounted engine. The airflow reaching the front of the ramjet would be moving faster, but at a lower pressure and so will not result in more air being compressed into the engine. It might even lose power.

    Ramjets rely on the air being forced and compressed under pressure into it's inlet for proper operation. Lower air pressure, such as that encountered at higher altitudes (or at the venturi's throat) result in less jet engine power output. Said aircraft jet engines have to fly faster in thinner air to achieve the same power. There is no power gain.


    .
    Last edited by AirDOGGe; 06-05-2011 at 12:06 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •