[burpg] Meeting Update 5/30/14, no meeting tomorrow 5/31.

  • From: Ben Ha <benha@xxxxxx>
  • To: "burpg@xxxxxxxxxxxxx" <burpg@xxxxxxxxxxxxx>
  • Date: Fri, 30 May 2014 23:37:44 -0400

Hey Everyone,

This meeting was sort of long but I think looking at this summary, it
really shouldn't have been.

We went over some parts of the Mark IIB for the people who attended so that
they could start their projects.

*Oxidizer Tank and Feed*
700 PSI
1000 PSI 1/4" Ball Valve for Vent
1000 PSI 1/4" Ball Valve for Fill
6000 PSI 1/4" Ball Valve for Pressurant
1000 PSI 1/4" Ball Valve Main Oxidizer
Volume: ~552.92 cubic inches
Thickness: 0.25 inches

Flat bulkheads with O-rings like the Mark IV tank. This means that we have
to spec the tank to a diameter that we can purchase O-rings for. Also must
be able to attach the assembly to threaded rods. Let's try to keep this
tank under 30" long.

We talked about reusing the exploded Mark III tank by chopping off the
blown out ends and keeping the intact tube but we were against it because
it seems like more work to make sure that tank could withstand the
pressures versus buying or building a new tank. We are leaning toward
buying a new tank off the shelf.

*Combustion Chamber*
500 PSI
Must incorporate an easy way to swap nozzles.

This part is a bit unclear to me and Cory is going to really guide this
part especially since he's on the team. So I'm going to let him answer any
questions about it. We know that this part has to fit the fuel grain, so
the group that's working on the fuel grain should talk to this group in
order to coordinate that. The simulation data outputs a fuel grain that's
13.14 inches long. So the combustion chamber should be at least 15 inches

*Fuel Grain*
13.14 inches long according to the MatLab code.
Initial Port Diameter: 1.42 inches
Final Port Diameter: 3.23 inches

 We want to test a singular circular port geometry which from what I
understand is a cylinder with a flat topped cone hollowed out of it. The
ends of the cone would be the port diameters. I think we'll have to cast
the fuel grain in two parts so if we could do one mold for the top half and
one mold for the bottom half, that would work well. This group should
design the fuel grain as well as the molds. We will 3D print the molds.

If we have time, it might be fun to experiment with other fuel grain
geometries, but let's not get ahead of ourselves.

*Ground Support*
Valve-Servo housing that can be screwed straight into that wooden blast
fence we have.

This team will be doing all the work to mechanically interface with the
valves and tanks that are on the ground as well as the hosing to the Mark
IIB itself. We're going to try to reuse as much of our current setup as
possible, but we want to redesign at least the valve housings because they
could be a lot better.

*Electronics Support*
For now, I think the Mark IV electronics will be enough to run the Mark
IIB, but there will be a lot of development with the liquid injection
thrust vector control. Dean is much more qualified than me to explain what
we need so I'm going to ask him to take charge of managing that part.

*Test Stand*
Peter had some good ideas about the test stand and so I think he should
take charge of the test stand design and construction. Please contact him (
petea383@xxxxxx) if you would like to work on the test stand. And I'm sure
Sindel (dsindel@xxxxxx) would be an excellent source of information for you
when you have any questions about that. I will try to get you some real
dimensions for it, but essentially I would like the whole Mark IIB assembly
that hangs from the test stand to be smaller than six feet. So if you aim
for an eight foot test stand, I think that would be really good.


Baseline standard nozzle

LITVC test nozzle

Molybdenum coating test nozzle

Aggressive minimum mass nozzle

Mk V scale down nozzle

I think Halstead has taken on the nozzles and so I'm confident that I don't
even have to mention it here, however if you would like to help with the
nozzles, I definitely suggest emailing Halstead (thalstea@xxxxxx) and
asking him what he needs help.

Mehmet has informed me that he and Dean are working on the injectors. He
said that so far, they'll need help with the analyses, but it sounds like
Justin Black from GE will be the expert on that. If you're interested in
the injectors, send Mehmet (meak@xxxxxx) or Dean (ddecarli@xxxxxx) an email
just to let them know. They may not need the help right now, but I'm sure
they'll appreciate it later on.

Please let me know if I've missed anything or gotten something incorrect.
If you have more questions, don't hesitate to contact me by email or phone,

Benjamin Ha
Boston University
Mechanical Engineering 2016
BU IS&T Desktop Services Student Lead Tech
Singh Imagineering Laboratory Lab Advisor
BU Rocket Propulsion Group Secretary

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