[sugpro] Re: Srm nozzle throat size
- From: Bill Kuker <bkuker@xxxxxxxxxxxxx>
- To: sugpro@xxxxxxxxxxxxx
- Date: Thu, 19 Feb 2015 21:52:12 -0500
Yeah, those screenshots are from very early work. It looks like the
attached screenshot now, which I think is correct.
-Bill
[image: Inline image 1]
On Thu, Feb 19, 2015 at 5:30 PM, Troy Prideaux <GEORDI@xxxxxxxxxxxxxxxx>
wrote:
> The geometry regression for the c-slot geometry is incorrect – at least
> it looks that way. Internal Corners (convex vertices) don’t regress out as
> sharp corners, but as a radius. If the corner starts out without any
> initial radius, the center point of the radius will be the point of the
> corner/vertex. Conversely, concave/reflex corners will regress **in**
> sharply (no radius)
>
>
>
> Troy
>
>
> ------------------------------
>
> *From:* sugpro-bounce@xxxxxxxxxxxxx [mailto:sugpro-bounce@xxxxxxxxxxxxx] *On
> Behalf Of *Bill Kuker
> *Sent:* Friday, 20 February 2015 5:47 AM
> *To:* sugpro@xxxxxxxxxxxxx
>
> *Subject:* [sugpro] Re: Srm nozzle throat size
>
>
>
> Yes, check out http://content.billkuker.com/projects/rocketry/software or
> https://github.com/bkuker/motorsim for the source code.
>
>
>
> The math is more or less based on SRM.xls, but it has more options for
> grain geometry.
>
>
>
> -Bill
>
>
>
> On Thu, Feb 19, 2015 at 12:18 PM, Steve Peterson <
> steve_peterson@xxxxxxxxxxxxx> wrote:
>
> I wrote my own--it's not that hard. Also, Bill Kuker wrote a program that
> is available--don't know the details, though. It's at
> content.billkuker.com
> --Steve
>
>
>
> On 02/19/2015 04:40 AM, Dan Harrison wrote:
>
> Thanks for the replies .
>
> Michael, that is a good idea with the bolt I will try that when I build my
> stand.
>
> Steve, is there a different software you use to sim motors? I know there
> is a program called burnsim but I was under the impression that was only
> for ap motors .
>
>
>
> Thanks,
> Dan
>
>
>
>
> On Feb 17, 2015, at 1:08 PM, Michael Monteith (Redacted sender "
> michael_r_monteith@xxxxxxxxx" for DMARC) <dmarc-noreply@xxxxxxxxxxxxx>
> wrote:
>
> One I've seen is where they pre load it with a weight and use a bolt
> underneath the load
> cell and adjust it to limit the load cell being pushed any further. Of
> course the bolt being
> locked in place once it's adjusted. That way you get the resolution by
> using a smaller
> cell but protect it from being pushed too far in the case of
> miscalculation or catostrophic
> event. Probably should be a standard procedure anyway to protect the load
> cell.
>
> Michael
> --------------------------------------------
> On Tue, 2/17/15, Steve Peterson <steve_peterson@xxxxxxxxxxxxx> wrote:
>
> Subject: [sugpro] Re: Srm nozzle throat size
> To: sugpro@xxxxxxxxxxxxx
> Date: Tuesday, February 17, 2015, 1:02 PM
>
> Hey Dan,
>
> I can't answer the first
> question since I don't actually use SRM, but
> the calcs it does are pretty accurate--the real
> question will be how
> accurate/reliable is
> your construction? The safe thing to do, if you've
> never tested a motor before, is to start with a
> load cell that is
> capable of much more
> thrust than you anticipate your motor will produce,
> especially if/when it CATOs.
>
> --Steve
>
> On
> 02/17/2015 09:35 AM, Dan Harrison wrote:
>
> Hello ,I'm looking to find some info
>
> on using Richard nakka's srm.
>
> Is there a way to change the
>
> nozzle throat size to match my motor? I tried using the
> nozzle erosion box but I'm not sure if that is the right
> way to do it.
>
> How
>
> accurate is srm ? I realize there are a lot of variables
> .but generally speaking if it calculates 25 lbs max thrust
> is that usually close to what it will measure on a test
> stand? The reason I ask is I'm building a test stand and
> I want to make sure I put the correct load cell on for my
> first test.
> Thanks,
>
> Dan
>
>
>
>
>
>
>
>
>
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