[AR] Re: Super Loki Dart design documents

  • From: "" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "JMKrell@xxxxxxx" for DMARC)
  • To: arocket@xxxxxxxxxxxxx
  • Date: Mon, 1 Sep 2014 22:14:35 -0400 (EDT)

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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