There's a machine for that at Wallops....
Bill
Sent from my iPhone
On Aug 21, 2014, at 11:29, Carl Tedesco <ctedesco@xxxxxxxxxxxxxx> wrote:
> Thanks Bill. Now to figure out how to spin a 21 foot long, 12"
diameter rocket.
> --- Carl
>
> On 8/21/2014 9:43 AM, Bill Claybaugh wrote:
>> Carl:
>>
>> I believe FAA is looking for the 6DOF moments which are required
inputs to any dispersion analysis.
>>
>> If your vehicle is fully axisymmetric the pitch and yaw moments
should be the same. However, that is rarely the case in the
payload and any asymmetry will induce coning unless balanced. This
is why dynamic balancing is required on all professional payloads.
>>
>> If you are flying a liquid I would strongly recommend dynamic
balancing the entire vehicle (a very good practice even if you are
flying a fully symmetric solid--density variations in the
propellant can influence stability). Static stability testing is
not sufficient.
>>
>> Bill
>>
>> Sent from my iPhone
>>
>> On Aug 20, 2014, at 15:45, Carl Tedesco <ctedesco@xxxxxxxxxxxxxx> wrote:
>>
>>> I am starting the process for getting a class 3 waiver for a
rocket launch. Most of the FAA required documentation looks
straight forward. One piece of information they require is "The
dynamic stability characteristics for the entire flight profile." A
static stability analysis is straight-forward, but I have never
done a dynamic stability analysis.
>>>
>>> How have folks on this list addressed this requirement? Is this
software driven analysis or just hand-calculations? Does anyone
have an analysis they could share? If software analysis is the
norm, can anyone point me to affordable software?
>>>
>>> --- Carl
>>>
>>> --
>>> Carl Tedesco
>>> Flometrics, Inc.
>>> 5900 Sea Lion Place, Suite 150
>>> Carlsbad, CA 92010
>>> tel: 760-476-2770 ext. 515
>>> fax: 760-476-2763
>>> ctedesco@xxxxxxxxxxxxxx
>>> www.flometrics.com
>
> --
> Carl Tedesco
> Flometrics, Inc.
> 5900 Sea Lion Place, Suite 150
> Carlsbad, CA 92010
> tel: 760-476-2770 ext. 515
> fax: 760-476-2763
> ctedesco@xxxxxxxxxxxxxx
> www.flometrics.com
>
>