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Another week has gone and the contractor has given excuses for not being back, I am at the point of contacting a lawyer due to the delays as winter approaches, Still hoping that the contracted work will be accomplished as it will cost me less than trying to get the money out of the contractor.
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For SpaceNut re #351
Thanks for telling us of the delays... It's possibly too late now, but escrow is the proven way to deal with questionable contractors.
I've seen it used by a large corporation. The contractor wanted money up front, and the corporation wanted to see the finished software product. What they agreed upon was an escrow account. The contractor could see the money, but it wasn't released until the work was done.
This may not be the only contractor you hire, so this might be an expensive learning opportunity.
PS ... the attorney's fees come out of the judgement against the plaintiff.
***
I logged in just now to report on testing of the Google Meeting system,
No camera found ... this happens after i use the system with another meeting package.
I'll have to restart the browser...
OK! Browser restart fixed the problem.
The waiting room will open at just before midnight UTC.
Now is 22:26 UTC
That will be 7 PM Houston and 8 PM New Hampshire
If PhotonBytes ever decides to join it will be midmorning in Australia.
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The waiting room is open at 23:59:59
gw Johnson logged in but his internet connection went down a few minutes later.
Weather is calm in Waco to it isn't weather.
gw was able to reconnect and we covered a number of topics. Along the way, GW showed me the Merlin Engine image in Wikipedia. I was struck by how closely it resembles the Merlin engine model we are using in the OpenFOAM topic.
I can easily imagine the original builder of the model tracing the outline of the engine from an image like the one in Wikipedia.
The shape is almost identical. The dimensions of the model may be different from the dimensions of the actual engine.
GW will continue looking for details. He did find what looks like the diameter of the throat.
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It is Google Meeting day once again for NewMars members !!!
The Waiting Room will open at midnight UTC as usual. 7 PM Houston 8 PM New Hampshire Mid-Morning in Australia
The link to join is provided in Post #1 of this topic.
I'm not expecting a huge attendance today! We have two members involved heavily in house projects.
That said, we someone who has not yet connected would be willing to give it a try, we've gained some experience using Google Meeting tools to take deep dives into the Internet investigating various technical issues that members bring up.
Starship has another launch coming up shortly.
Dream Chaser is postponed to 2026 at the earliest.
NASA appears to be hoping to achieve at least the Moon Circle flight with Artemis.
China is quietly massing experience with their space station. They have avoided losing a single Taikonaut.
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Systems check at 23:33 went well.
We have a successful run of the OpenFOAM project after a series of failures using a high performance solver called shockFluid.
In the end, we tried an easy going solver named rhoPimpleFoam, and managed to get through a run of .01 seconds without a crash.
We'll have something to look at this evening, if there is time and interest.
Otherwise we can discuss the orbit of the Moon which has such an influence on the living creatures of Earth.
For some reason I was totally unaware of the range of intervals between the appearance of the moon on one day and it's comparable appearance the next.
We have a starship flight coming up.
Other space launch entities have been busy.
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We're off to a good start!
kbd512 is back online after a very busy time.
GW Johnson is with us from McGregor Texas, with bright afternoon sunshine showing through the porch sliding door windows.
We started out with discussion of GW's sale of a VW bus to an enthusiast who is planning to put it back into operation.
That led to (to me surprising) discussion of how the original VW engine design has continued into the present day. Even the Chevrolet Corvair engines have persisted into the present day.
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Today is Google Meeting day for NewMars..
GW Johnson has a new study to show ... this one is on Moon landing, including access to the poles
Work on the extendedMerlin has made some progress...
We'll have animation to show of a successful 9 hour run showing hydrogen flowing through the entire system at 300 Kelvin.
Next week, this demonstration at 300 Kelvin will be followed by addition of (carefully designed) draining of the initial stash of hydrogen. The first time we tried this the hydrogen drained before the new addition arrived and the equation solvers went bonkers. The new strategy is to wait to begin draining until hydrogen is showing up at the nozzle after the long trip through the heat pipe.
Today's animation will clearly show the effect of drag on the plume of new hydrogen as it exits the nozzle ... the part of the plume that retains pressure greater than 1 bar is able to exit through the existing outlet, but the part that was slowed by drag stays in the engine compartment and circulates to cause turbulence which slows down processing due to the extra machine cycles needed to compute the flows. On the other hand, it ** is ** interesting to see vortex forming and moving around in the compartment.
The Real Universe test equipment would not have this problem if it were run in vacuum. The simulation cannot start out with vacuum conditions because the equations need enough mass to chew on, but simulating sea level conditions ** is ** achievable, so we've implemented that solution. A test article ** could ** be run at sea level, so the simulation's predictions would (presumably) come close to matching reality.
Today's demonstration will (hopefully) include showing how graphs can be generated from the data. I'm just beginning to learn about this capability, so only have one graph to show at this point. It shows how pressure varies due to the turbulence reported earlier.
All are welcome. The link to join the meeting is provided in Post 1 of this topic.
Each meeting features at least one deep dive into the Internet, led by kbd512, when he is able to attend.
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System check at 20:00:00 UTC went well...
We'll be back here in an hour.
All are welcome. Just use the link in post 1 of this topic.
The Waiting room is open at 23:59:23
*** That was another interesting meeting.
kbd512 was in fine form this evening! We started out with a deep dive based upon his recent post about masers.
In the midst of that, GW Johnson arrived, so we discussed how maser technology might help with SPS.
About midway through the evening, we branched into review of GW''s most recent paper on return to the Moon, using systems of his design based upon the successful Centaur hydrogen/LOX vehicle.
We wrapped up the hour with a brief review of the status of the extendedMerlin OpenFOAM study, with review of the results of the recent successful 9 hour run with pure hydrogen at 300 Kelvin. The run showed that we seem to have the model functioning well enough to not crash, but it did consume far more machine cycles than necessary due to a misconfiguration of the outlet panel. That misconfiguration was by design. Outlet to vacuum caused the run to crash, because unlike Ma Nature, OpenFOAM equations need some mass to chew on, and when we exhaust the gas to vacuum too early, the equations chomp on nothing and complain. the next run will start in a few minutes. It will run for 9 hours or so, with the outlet ramping up gently towards vacuum in increments designed to match the input of hydrogen at the intake. We can see that the intake settings are working well, because the hydrogen reaches the engine compartment and swirls around there. Here are some images of the successful 9 hour model.
<< images go here>>
The pressure display shows the arriving hydrogen backed up while trying to push through the nozzle:
http://40.75.112.55/phpBB3/download/file.php?id=45
The temperature display shows gas swirling around in the engine compartment. Temperatures are near 300 Kelvin, but excursions above occur because energy is added to the system by the arrival of fresh hydrogen gas from the intake pipe:
http://40.75.112.55/phpBB3/download/file.php?id=46
The Velocity display is the most interesting. It clearly shows the consequence of configuring the back wall (on the right) to only pass gas that has a pressure greater than one bar. Because gas is slowed on it's way to the back wall from the nozzle, it loses pressure and thus cannot exit, so it bounces back and causes turbulence. the next run will ease the congestion by ramping down the back wall slowly toward vacuum but stopping well shy of vacuum.
http://40.75.112.55/phpBB3/download/file.php?id=47
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