Saturday, October 27, 2018

Rocket Whiles

TL;DR I bought the Madcow kit to use my Eggtimer rocketry electronics and to test dual deployment. I suppose for simplification, the Madcow Torrent could be flown in non dual deployment mode with a J350. This simplification is claimed on the Apogee website.  
     
   There is a forcing function in my subconscious that I have to be careful of:  
     
   When I was a child, I built several Estes rockets: Alpha, Eliminator, NOVA Payloader, Mosquito, etc. I also participated in a rocketry activity in high school where we fiberglassed our own tubes, learned about center of pressure and center of mass, and operated some dawn of the millennium   
   version of rocket software. I also attended several meetings at the university where they were building an anodized aluminum rocket, but I quit going because I could not follow what was going on.  
     
   I went to Airfest 24, and it became obvious to me I had forgotten a lot about rocket construction. I built a Nike Smoke, which is in the Estes Pro-Series II . This taught me about inset fins, motor mount construction, and motor retainers. Since I flew with an Aerotech DMS H135W at a later time, I learned how to  
   properly prepare a motor with an added black powder ejection charge. This was not my first experience with a composite motor. I thank a guy at Airfest for giving me a Quest B6-4 (If I can recall correctly).   
     
   I built a Wildman Punisher Mini. I will need to do a bit of work before it is flight ready. Adding a motor retainer to the rear, and inserting my spent H135W motor gave me worries that the center or gravity was too close to the center of pressure. I may need to add weights to the nose cone  
   to shift the center of gravity forward away from the center of pressure. If I chose to use an H, OpenRocket suggests that I will exceed Mach. This velocity will also give me a great altitude assuming I have the proper delay and assuming I have enough momentum to overcome drag. This means that  
   I will have trouble finding this rocket if I do not add a tracking advice.  
     
   When working with a friend, we found it necessary to not attach the kevlar shock cord directly to the motor mount tube. Doing so would require cutting a slit in one of the motor mount rings, and it would have to go all the way through to fit.   
   This would break the annulus. With enough epoxy, this probably would not have been a big deal. Our solution was to attach the shock cord to a mounted ring with a carbon fiber section attached. 
<img src='https://farm2.staticflickr.com/1919/44860651114_feb3b7521d_z.jpg' / width="200">
   I am not sure how well this will sustain repeated flights. The exposed area is small, as is the exposure time.  
     
   The PML Tethys seems like a great kit. I like that I saw a link to the Kwik Switch instructions. I heard that rockets were sometimes built that allowed for different diameters of motors, now I have seen a method for accomplishing this. However, I do not see a big difference in the rocket from what I have done previously.  
     
   This gets to an underlying motive. I'm frustrated that I have applied to SpaceX, Boeing, Virgin, and I am continually turned away. I feel I need to shatter the belief that doing a Masters in Chemical Engineering with no engineering internship experience is somehow good enough.   
   I am seeing inroads with my above-average computer experience (Linux user, developer experience, meetup founder, et al.), but this really was for a passion project to build a community to build open source space hardware. I ultimately wanted to build hardware. My mistake with the software was to make it too complex with niche technolgy which led me to ultimately drift from the developer community and their technology.   
   This made me an overall weak developer, or at least one with knowledge gaps. I discovered this with my last position. Following events led me to question whether I really wanted to be a developer or whether I wanted to be an engineer. I assumed from experience, that each choice would require considerable time to perfect. I know I have spent seven years on my software project, and it took considerable time to get a Masters degree.  
     
   I remember talking to an employee at SpaceX who gratuitously gave of their time. They told me a good way in was to build something. I did, and it turned out to be a number of potato cannons (if I have the timeline correct). I had heard about them when I was younger, and it sounded fun. As I did some of my work at a hackerspace, this led to a joke, "why don't you send a potato to the moon?". It turns out there was an Aerospace Engineer that some in the group had seen at Defcon. They suggested I talk to him. This led me to a team called AlphaCubesat, which was participating in the NASA Cubequest challenge to send a cubesat on the SLS. This exposed me to Systems Engineering, Radiation hardened electronics, the Deep Space Network, Hoffman transfer orbits, and weirdly an opportunity to talk about my software project at Hacker Dojo in Mountain View.   
     
   During the same year, I had the opportunity to volunteer for development for the Integrated Space Plan website. I chose this path, and abondoned involvement in AlphaCubesat. I liked that they were using a linked data and semantic web approach to represent information about companies and projects in a temporal fashion. I learned a lot about the new space industry then, as well as the National Space Society / ISDC, and SEDS.   
     
   I had the opportunity to return to ISDC when it was in St. Louis, and when it was in Los Angeles. After I missed the event in Los Angeles, I recalled that there truly were some amazing people there, both as speakers and volunteers. I discovered there was a list of speakers available. This led me to start contacting them. However, my activities through the passing months led one to observe that I was a bit scattered, and really needed to build something. My software project was not that persuasive, and would require deeper embedding (perhaps within an organization) for success.   
     
   While I was reaching out to people I remembered from AlphaCubesat and the Integrated Space Plan adventure, I discovered that the rockets that were being used to launch smallsats were not all that different from high powered rockets (at least in size). Thus, I thought it would be appropriate to begin exploring high powered rockets for something to build.  
     
   I have observed the student competitions and found that they range from launching an egg undamaged to a particular altitude to space piercing liquid fuled behemouths. I am not a student, but I would like to emulate some of the projects. Since my degree is in Chemical Engineering I feel that I would be particularly suited for a propulsion engineering job description.   
   However, I do not have the experience that I would have obtained had I participated in a student rocket competition. Therefore, I am imagining a Level 2 certification, then solid research motors, then hybrid rockets, and then liquid fueled rockets at the FAR site. At some point, I hope one of the companies I am applying for likes me. This will be expensive, so I am trying to learn the most I can at each iteration of building.

Wednesday, October 24, 2018

rocket links

https://www.rocketreviews.com/how-to-make-a-nose-cone.html


https://www.instructables.com/id/Make-your-own-Kraft-Paper-Tubes/

 ps://www.youtube.com/watch?v=qf-l18fhnJM&list=PLyjfBfFp2v2qI3xi5untijgBGZK630Jtj

Tuesday, October 23, 2018

flow through pipe for boundary condition experiments

Starting here:

OpenFoam CFD Tutorial | Laminar Flow Through a Pipe 3D | Part 1/4- Case Setup

https://www.youtube.com/watch?v=6aIKrVnHYmg


Friday, October 19, 2018

openfoam compound success

caelinux@caelinux:~/OpenFOAM/caelinux-4.1/run/tutorials/incompressible/icoFoam/cavity-brent/cavity$ ideasUnvToFoam cavity_compound3.unv
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.1                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 4.1
Exec   : ideasUnvToFoam cavity_compound3.unv
Date   : Oct 20 2018
Time   : 00:43:51
Host   : "caelinux"
PID    : 20916
Case   : /home/caelinux/OpenFOAM/caelinux-4.1/run/tutorials/incompressible/icoFoam/cavity-brent/cavity
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Processing tag:164
Starting reading units at line 3.
l:1
units:"  SI: Meter (newton)"
unitType:2
Unit factors:
    Length scale       : 1
    Force scale        : 1
    Temperature scale  : 1
    Temperature offset : 273.15


Processing tag:2420
Skipping tag 2420 on line 9
Skipping section at line 9.

Processing tag:2411
Starting reading points at line 20.
Read 1722 points.

Processing tag:2412
Starting reading cells at line 3467.
First occurrence of element type 11 for cell 1 at line 3468
First occurrence of element type 44 for cell 165 at line 4326
First occurrence of element type 115 for cell 1045 at line 7806
Read 800 cells and 1740 boundary faces.

Processing tag:2467
Starting reading patches at line 9408.
For group 1 named movingWallRight trying to read 20 patch face indices.
For group 2 named frontAndBackFaceRight trying to read 800 patch face indices.
For group 3 named fixedSubWallRight trying to read 40 patch face indices.
For group 4 named movingWallLeft trying to read 20 patch face indices.
For group 5 named frontAndBackFaceLeft trying to read 800 patch face indices.
For group 6 named fixedSubWallLeft trying to read 40 patch face indices.

Of 1740 so-called boundary faces 20 belong to two cells and are therefore internal
Sorting boundary faces according to group (patch)
0: movingWallRight is patch
1: frontAndBackFaceRight is patch
2: fixedSubWallRight is patch
3: movingWallLeft is patch
4: frontAndBackFaceLeft is patch
5: fixedSubWallLeft is patch

Constructing mesh with non-default patches of size:
    movingWallRight    20
    frontAndBackFaceRight    800
    fixedSubWallRight    40
    movingWallLeft    20
    frontAndBackFaceLeft    800
    fixedSubWallLeft    40

End

openfoam compact error message

caelinux@caelinux:~/OpenFOAM/caelinux-4.1/run/tutorials/incompressible/icoFoam/cavity-brent/cavity$ ideasUnvToFoam cavity_compound3.unv
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.1                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 4.1
Exec   : ideasUnvToFoam cavity_compound3.unv
Date   : Oct 20 2018
Time   : 00:28:25
Host   : "caelinux"
PID    : 20727
Case   : /home/caelinux/OpenFOAM/caelinux-4.1/run/tutorials/incompressible/icoFoam/cavity-brent/cavity
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Processing tag:164
Starting reading units at line 3.
l:1
units:"  SI: Meter (newton)"
unitType:2
Unit factors:
    Length scale       : 1
    Force scale        : 1
    Temperature scale  : 1
    Temperature offset : 273.15


Processing tag:2420
Skipping tag 2420 on line 9
Skipping section at line 9.

Processing tag:2411
Starting reading points at line 20.
Read 1722 points.

Processing tag:2412
Starting reading cells at line 3467.
First occurrence of element type 11 for cell 1 at line 3468
First occurrence of element type 44 for cell 165 at line 4326
First occurrence of element type 115 for cell 1045 at line 7806
Read 800 cells and 1740 boundary faces.

Processing tag:2467
Starting reading patches at line 9408.
For group 1 named fixedWallRight trying to read 60 patch face indices.
For group 2 named movingWallRight trying to read 20 patch face indices.
For group 3 named frontAndBackFaceRight trying to read 800 patch face indices.
For group 4 named fixedWallLeft trying to read 60 patch face indices.
For group 5 named movingWallLeft trying to read 20 patch face indices.
For group 6 named frontAndBackFaceLeft trying to read 800 patch face indices.

Of 1740 so-called boundary faces 20 belong to two cells and are therefore internal
Sorting boundary faces according to group (patch)
0: fixedWallRight is faceZone
1: movingWallRight is patch
2: frontAndBackFaceRight is patch
3: fixedWallLeft is faceZone
4: movingWallLeft is patch
5: frontAndBackFaceLeft is patch

Constructing mesh with non-default patches of size:
    movingWallRight    20
    frontAndBackFaceRight    800
    movingWallLeft    20
    frontAndBackFaceLeft    800

--> FOAM Warning :
    From function Foam::polyMesh::polyMesh(const Foam::IOobject&, const Foam::Xfer<Foam::Field<Foam::Vector<double> > >&, const cellShapeList&, const faceListList&, const wordList&, const wordList&, const Foam::word&, const Foam::word&, const wordList&, bool)
    in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 595
    Found 80 undefined faces in mesh; adding to default patch.
Adding cell and face zones
 Face Zone fixedWallLeft     60
ideasUnvToFoam: ideasUnvToFoam.C:1271: int main(int, char**): Assertion `noveau > -1' failed.
Aborted (core dumped)

Saturday, October 13, 2018

Open foam weekend notes

Kappa Epsilon and Reynolds Stress Model mentioned here:

https://cfd.direct/openfoam/user-guide/v6-turbulence/


Meshing for OpenFoam using Salome. Cavity example

https://www.youtube.com/watch?v=8XugdrYyBSg

mesh on Salome to OpenFOAM

https://www.youtube.com/watch?v=Iw7lqV26tGs

Salome 2D meshing for OpenFOAM tutorial

https://www.youtube.com/watch?v=7l3ea7nwSrc

Lesson 4. Basic of Salome-Platform. Partition Operation and Meshing Multibody Partitions

https://www.youtube.com/watch?v=UAxurz_g5RE


Multibody_mesh in Salome Meca

https://www.youtube.com/watch?v=EcA5I9orOCg


Bonus: FEA with Code Aster. https://www.youtube.com/watch?v=7p5mQuJIZdI

See also: http://feaforall.com/category/open-source-fea/