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Re: PV Dirigible Prop Alternative To Super Pressure

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Subject Re: PV Dirigible Prop Alternative To Super Pressure
Date Fri, 10 Jun 2016 21:22:43 -0000
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Bret Cahill <bretcahill@aol.com> wrote:
>> >> For the third time, why is the Reynolds number of any sphere, of any size,
>> >> and of any material always the same number?
>> > 
>> > If the diameter or "characteristic dimension" is larger or smaller, you get a larger or smaller Nre.
>> > 
>> > If the velocity in inversely proportional to diameter then the Nre is the same for all sizes of that shape in that fluid, i.e. a golf ball going 300 km/hr has the same Nre as a cyclist helmet going 30 km/hr and the air holes in the helmet actually _reduce_ drag like the dimples on the golf ball reduce drag.
>> > 
>> > Maybe you meant the Reynolds number can be applied to any size object.
>>  
>> The Reynolds number is directly proportional to the diameter of the
>> cross section, so the comment about size is incorrect.
>> 
>> Equal sized spheres, no matter the material, be they soap bubbles or lead,
>> have the same Reynolds number.
> 
> The speeds would need to be the same as well, a rare coincidence because
> soap bubbles always move slowly w/ respect to wind speed.

As the Reynolds number is directly proportional to velocity, comparing
Reynolds numbers at differing speeds is at best pointless and at worst
plain idiotic.

-- 
Jim Pennino

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PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-04 12:47 -0700
  Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-05 02:11 +0000
    Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-04 22:22 -0700
      Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-05 17:36 +0000
        Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-05 13:52 -0700
          Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-05 22:56 +0000
            Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-08 00:57 -0700
              Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-08 19:27 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Mahipal <mahipal7638@gmail.com> - 2016-06-08 19:16 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-09 02:52 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Mahipal <mahipal7638@gmail.com> - 2016-06-09 06:55 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-09 16:22 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Mahipal <mahipal7638@gmail.com> - 2016-06-09 13:23 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-09 21:14 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Mahipal <mahipal7638@gmail.com> - 2016-06-09 14:49 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-09 19:46 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-10 05:53 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-10 10:07 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-10 17:49 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-10 21:22 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-10 19:40 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-11 05:00 +0000
                Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-11 01:13 -0700
                Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-11 17:38 +0000
  Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-08 00:58 -0700
    Re: PV Dirigible Prop Alternative To Super Pressure noTthaTguY <abu.kuanysh05@gmail.com> - 2016-06-08 07:23 -0700
    Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-08 14:18 -0700
      Re: PV Dirigible Prop Alternative To Super Pressure Sergio <invalid@invalid.com> - 2016-06-08 16:26 -0500
      Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-08 21:41 +0000
        Re: PV Dirigible Prop Alternative To Super Pressure benj <nobodyxx@gmail> - 2016-06-08 20:23 -0400
          Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-09 00:34 +0000
            Re: PV Dirigible Prop Alternative To Super Pressure benj <nobodyxx@gmail> - 2016-06-08 21:07 -0400
              Re: PV Dirigible Prop Alternative To Super Pressure "hanson" <hanson@quick.net> - 2016-06-08 19:22 -0700
              Re: PV Dirigible Prop Alternative To Super Pressure jimp@specsol.spam.sux.com - 2016-06-09 02:36 +0000
  Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-08 14:42 -0700
    Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-09 20:20 -0700
      Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-10 10:10 -0700
        Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-11 11:02 -0700
      Re: PV Dirigible Prop Alternative To Super Pressure Bret Cahill <bretcahill@aol.com> - 2016-06-10 20:11 -0700

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