[AR] Re: Super Loki Dart design documents
- From: "Troy Prideaux" <GEORDI@xxxxxxxxxxxxxxxx>
- To: <arocket@xxxxxxxxxxxxx>
- Date: Tue, 2 Sep 2014 12:25:31 +1000
Which is kind of the point I was making.
Troy
The higher altitudes from the Viper darts is the result of the 57 lbs of
propellant compared to the 37 lbs in the Super Loki.
In a message dated 9/1/2014 3:46:44 P.M. Pacific Daylight Time,
GEORDI@xxxxxxxxxxxxxxxx writes:
>O25000 great stunt motor but not very efficient. Larger diameter
>dramatically increases drag, particularly in the le, dense atmosphere.
Not necessarily - for the same aspect ratio and everything else being equal, a
larger diameter (or actually larger) rocket should be more efficient than a
smaller one in an atmosphere purely due to *drag* - a larger rocket is *less*
affected by drag due to the cube-square law. Of course (with everything being
equal), larger rockets generally go faster due to this fact and will, as a
consequence, experience more drag so everything isn't equal after all and
because of this will probably be less efficient. Nevertheless, it should go
higher hence demonstrated why the operational ceilings for the larger Viper
darts are considerably higher than the smaller Loki.
The O25000 probably is a bit short for a really efficient dart motor, but its
burn time will go some way in making up for that with an efficient dart.
>
>This is why all the folks flying N5800s are very amusing. No doubt
>entertaining but highly inefficient. Much of the energy of the motor goes
>into drag and heat rather than altitude.
Indeed. I'm guessing the attraction is the engineering challenge of dealing
with the loads experienced with such an aggressive flight profile. Flying such
flight profiles is incredibly inefficient, however well engineered *boosted
darts* are the most efficient method of obtaining a certain altitude within an
atmosphere and gravity field.
Troy.
>
>K
>
>Ken Biba
>Novarum
>Managing Director and CTO
>+14155775496
>
>
>> On Sep 1, 2014, at 1:28 AM, "Monroe L. King Jr."
><monroe@xxxxxxxxxxxxxxxxxx> wrote:
>>
>> Yeah, that motor would do it. I just can not afford that one.
>>
>> Monroe
>>
>>> -------- Original Message --------
>>> Subject: [AR] Re: Super Loki Dart design documents
>>> From: "Troy Prideaux" <GEORDI@xxxxxxxxxxxxxxxx>
>>> Date: Sun, August 31, 2014 8:22 pm
>>> To: <arocket@xxxxxxxxxxxxx>
>>>
>>>
>>> That O-25000 would be a very sweet motor for a boosted dart :) Very
>sweet indeed. What was the 5" variant of the Loki again? Viper?
>>>
>>> Troy
>>>
>>>> -----Original Message-----
>>>> From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
>On
>>>> Behalf Of Mark C Spiegl
>>>> Sent: Monday, 1 September 2014 12:39 PM
>>>> To: arocket@xxxxxxxxxxxxx
>>>> Subject: [AR] Re: Super Loki Dart design documents
>>>>
>>>> Monroe L. King Jr. wrote:
>>>>>> So I guess I need to calculate the burn rate and see what COTS has to
>>>> offer in
>>>>>> that ball park. Who has the fastest COTS propellant? Has anyone got
>any
>>>> hard
>>>>>> data on that? I'm sure someone out there in Arocket land already know
>>>> who's got
>>>>>> the hottest propellant.
>>>>
>>>> Cesaroni O-25000???
>>>> It's a 5 inch motor but might work.
>>>>
>>>> Cesaroni N-5800
>>>> Is a 4 inch motor but only 20kNS thrust
>>>>
>>>> For home brew, Kosdon had some quick burning motors. You might find the
>>>> formulas online these days.
>>>>
>>>> -->MCS
>>
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