[sugpro] Re: Verifying Motor Performance Through Flight Tests
- From: Bill Kuker <bkuker@xxxxxxxxxxxxx>
- To: sugpro@xxxxxxxxxxxxx
- Date: Tue, 24 Feb 2015 08:26:45 -0500
How about a load cell between the motor and airframe plus an
accelerometer? That would just leave the changing mass of the fuel to
account for.
Bill
On Tue, Feb 24, 2015 at 2:53 AM, Andrej Vrbec <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
> Air density was routinely measured in 50's and 60's by a falling sphere
> method. See here for example:
> http://deepblue.lib.umich.edu/bitstream/handle/2027.42/70398/JAPIAU-27-7-706-1.pdf?sequence=2&isAllowed=y
>
> Andrej
>
> ------------------------------
> *From:* "shawn.mchatten@xxxxxxxxxxx" <shawn.mchatten@xxxxxxxxxxx>
> *To:* sugpro@xxxxxxxxxxxxx
> *Sent:* Monday, February 23, 2015 11:47 PM
> *Subject:* [sugpro] Re: Verifying Motor Performance Through Flight Tests
>
> Hahaha! I think I got it. Although.... do we really need humidity, temp and
> pressure or are they all just variables to give us air density which is what
> we really want. And if there was some way to measure air density directly
> would that not be more helpful. One way to measure viscosity is to drop an
> object of "standard" mass and shape through the substance and measure the
> rate of descent. So if we flew a rocket to 500m and pitched a 10cm/500g cube
> out the side with a 50cm square chute (or whatever other "standard" object we
> can make up) and measure it's descent would that not be all the data we need
> to measure air resistance directly. It's just a matter of making an easily
> repeatable standard. Maybe a tube or sphere instead of cube and streamer
> instead of parachute.
>
>
>
>
> Shawn
>
>
>
> On 2015-02-23 16:27, Michael Monteith wrote:
> > Com on. Keep up. lol It's really just figuring out what it would
> > take to determine motor performance
> > through actually flight testing. I do like your idea though. Just
> > measure things like temperature,
> > humidity, and pressure on the way down so you can correct for air density.
> >
> > Thanks Shawn
> > Michael
> > --------------------------------------------
> > On Mon, 2/23/15, shawn.mchatten@xxxxxxxxxxx <shawn.mchatten@xxxxxxxxxxx>
> > wrote:
> >
> > Subject: [sugpro] Re: Verifying Motor Performance Through Flight Tests
> > To: sugpro@xxxxxxxxxxxxx
> > Date: Monday, February 23, 2015, 3:54 PM
> >
> >
> > Not sure I'm following all this conversation but
> > instead of a balloon can you gather data from a parachute
> > recovery on the way DOWN instead of on the way up to
> > establish air density etc. For that matter are there any
> > papers that show air density or viscosity based on a
> > specific parachute and mass configuration. If not that would
> > be a cool standard to create for the community.
> >
> > Shawn
>
>
>
>
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