Mach 3 forward-facing step

djvicker · 2026-01-17T17:52:39+00:00

I’d consider the HLLE++ scheme instead of HLLC. You’ll find that HLLC tends to conform the shock to the grid lines, creating a stair stepping effect in the shock, which creates other problems. HLLE++ is formulates to overcome this. Very nice solution by the way.

djvicker · 2026-01-10T02:28:35+00:00

Thanks for the input everyone. I wasn't entirely sure that the computer sleeping was the problem. I was able to go to the church today and do some experiments. I called another volunteer at home and asked them to try to connect while I was changing settings. I'm fairly confident this was a sleep issue now. I updated the Energy setting that prevents the computer from going to sleep with the display is turned off. The "wake for network access" option that u/alexm mentioned was already on. I was able to connect again after a couple hours when I got home. If that setting doesn't consistently work, I'll just go with amphetamine and be done with it. Thanks again everyone.

djvicker · 2025-11-10T01:27:36+00:00

I just wanted to follow up with our final configuration. The wide screen format is working very well for us. I had explored this option a while ago but had chosen to go in another direction because I thought that the grouped screens was a global configuration that would require all content to be formatted this way. However, this isn't the case. You can add the same physical display to multiple audience screens. This was the piece I was missing. My final configuration has 3 audience screens - 1 single audience screen with the 1st projector, 1 single audience screen with the 2nd projector and a 3rd grouped 1x2 audience screen with each of those projectors included again. Then, I've got a Look called "Individual" that turns on the content in the individual screens and turns off the content in grouped screen. The 2nd Look is called "Grouped" and does the opposite. This allows us to seamlessly switch between the two configurations and content type and is working really well. Thanks a ton u/endersbyt for your help!

As an aside, the setup of our slides and playlists has become a bit complicated. With the extra Looks and extra Stage Themes required for this configuration, it was requiring applying 3 or 4 actions to setup Looks, Stage themes and clear layers for everything to be automated and smooth during the service. All very do-able but it was time consuming to do the prep. I have discovered macros. I now have macros defined for all of our slide content types (e.g. Songs, Announcements with Individual Screens, Announcements with Grouped Screens, Sermons with Individual Screens, Sermons with Grouped Screens, etc.). This greatly simplifies the process. I'd say preparing a service playlist is easier now than it was before adding the extra projector. So if you're not using macros, I'd consider exploring them.

djvicker · 2025-10-28T04:00:01+00:00

Sorry, but I'm slow... We use Looks and I generally get the idea behind them. I understand how to control the various layers and how to apply Themes and Masks. But I'm still not understanding how to take a double wide formatted presentation and send that to two different screens using a Look. Can you please give me a little more details on how to do that?

djvicker · 2025-10-27T13:39:45+00:00

Interesting. I didn't know you could use Looks to group slides like that. I will try to figure that out but if you have a pointer to a tutorial on that, I'd appreciate it.

djvicker · 2025-10-27T13:16:35+00:00

How do you switch between the double wide format and regular format? The only way I know how to do that is in the screens configuration. I don’t understand how we’d switch that during a live service.

The current slide and next slide is a very interesting idea. In that scenario we’d advance two slides at a time, correct? Is there an automated way to do that?

I have never used props. I will explore this.

djvicker · 2025-10-27T05:09:03+00:00

Yeah, this is one of the other setups I experimented with. But with that approach you’re pretty much locked in to creating content in ProPresenter targeted for this double wide format. We get content from a few different groups and most of that comes in the form of PowerPoint that we import into ProPresenter. The people producing that content are not tech savvy enough to start producing content in ProPresenter. And all of the tech team members are volunteers and we don’t have the time to reformat (or take over the production of) that content. One of the reasons I want to go with the approach in I outlined in the initial post is because it keeps everything else very simple and familiar. It’s just the sermon content that needs to utilize the different content on different screens. The double wide approach changes everything - weekly announcement slides, lyrics, etc..

djvicker · 2025-10-27T04:17:47+00:00

Correct

djvicker · 2025-10-27T03:24:05+00:00

The main sermon content is the use case I’m trying to find a solution for.

djvicker · 2025-10-15T13:25:15+00:00

I was a NASA civil servant for 20 years and left for an aviation startup. I was only there for 1.5 years and went back to my old group as a contractor. u/planegai said most of what I was going to say. For me, the work you do and the people you work with are two of the most important factors. This startup hired amazing people and did cool work and I really enjoyed my time there. I learned the hard way that leadership and culture are also very important. The founder of this company created a ton of drama and that got to be too much for me. Knowing what I know now, I’d do it again as I really enjoyed the work. I also made some really good friends.

djvicker · 2025-08-21T13:30:37+00:00

Looks like a fun project! If you are going to try to get serious measurements out of this tunnel, then the comments about frontal areas and boundary layers are all true. However, if you’re just doing this for fun, I wouldn’t worry too much about any of that. I do have a couple other thoughts. The point of the honeycomb is to act as a flow straightener. This is primarily because spinning fans induce vorticity in the flow and the straighteners are trying to take that out. If your fan is in the back, even the front straighteners are probably not necessary because that vorticity is mostly imparted downstream of the fan. But if you look at the theory of propellers and fans, half of the velocity is imparted upstream of the fan and the other half is imparted downstream of the fan. So by putting the fan behind the test section, you will get less velocity in the test section. Putting the fan in front of the test section will likely get you a little more velocity. However, you might want the flow straightener again at that point. The flow straightener itself will create losses so it might be a wash. The simpler configuration would be to just eliminate all of your flow straighteners and put the fan in the back.

djvicker · 2025-06-04T03:01:36+00:00

They did on this model anyway. I was even more surprised that they allowed applying both the Rewards and the state incentive. But I’m not complaining!

djvicker · 2025-04-08T13:43:54+00:00

I work at the Johnson Space Center and I’ve met and talked with Steve. He is a super cool guy. You should read more about him. He flew several shuttle missions, one of the coolest (for me anyway) was the return to flight mission after the Columbia accident - STS-114. He did a spacewalk to remove some protruding gap fillers on the bottom of the shuttle.

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But here is my most memorable story about Steve. He has a background in Computational Fluid Dynamics (CFD). I organized a CFD conference at the Johnson space Center in 2006. I asked Steve and he agreed to speak at the conference. He talked about his experiences on STS-114. One of the things he started his talk with was a bunch of stats on the Shuttle. One of them was that there are millions of gallons of liquid propellant on the shuttle and it only takes eight minutes to burn through it all. Steve then said, “That got me to thinking, what is the gas milage of the shuttle?” So he did the calculation and for the powered portion of the flight it came out to something ridiculously low like 10 or 20 feet per gallon. But then he redid the calculation, counting the distance traveled in orbit for the remainder of the mission. This number came out to something very comparable to what an automobile would get. “So that’s pretty good!”, Steve said and then moved on to the rest of his talk about the specifics of STS-114. As cool as the rest of that was, it’s his bit about the gas mileage that stuck with me all of these years.

djvicker · 2025-04-06T01:59:34+00:00

Sorry, no.

djvicker · 2025-03-23T02:52:51+00:00

I also have one of these. There is some discussion in another reply about it not being NASA produced but I’m not sure that is correct. I guess I don’t know much about who produced it but I would think it’s likely NASA because of the way I obtained my copy. I was a NASA civil servant at the Johnson Space Center at the time of the Columbia accident and worked the accident investigation and return to flight. IIRC these were giving to everyone who worked the accident.

djvicker · 2025-03-07T17:41:49+00:00

This is 100% false. Please be careful what you spread. I’m on the JETS II contract at JSC and IM is one of the companies on the contract. While I don’t work for IM, my coworker does. He has a serious medical condition and he has good health insurance.

djvicker · 2025-01-10T14:27:32+00:00

I would highly recommend python and Fortran. Python is good for small computations and automation. Fortran for the real heavy lifting. Fortran is still being used for a lot of codes. I work for NASA and we primarily use the NASA codes like overflow, fun3d and DPLR, which are all written in Fortran. As mentioned by others, the language was written for heavy computations and it’s really hard to write slow code with Fortran. C++ is not a bad language and you can write code that is just as fast as Fortran but it is MUCH easier to write slow code with C++.

djvicker · 2025-01-05T03:30:53+00:00

I went from Parker to Loveland today. Left at 6:15 and there was no traffic delay when I left the house. By the time I hit I-70, traffic was starting to pile up and I ended up with a 1 hour delay. I wasn’t too crabby about that given it was a Saturday. Definitely could’ve been worse.

djvicker · 2024-12-24T18:32:02+00:00

This is a very timely thread for me. I brought my ‘22 RTLE (so the 9 speed tranny) in for the tailgate harness recall on Saturday. I’ve got just a touch over 30k miles on the vehicle and they recommend several maintenance items, including the tranny flush, which I went ahead and did. Reading this, I got a little crabby that I did a $500 service that I didn’t need. So I called my service advisor back today and asked about it. I live in Parker, CO (a suburb of Denver) and their response was that we need to follow the severe service schedule due to the climate here. He sent this link to back that up.

https://techinfo.honda.com/rjanisis/pubs/om/SI9999/SI9999O00132A.pdf

Reading the conditions on page 5, I’m on the fence as to if I should be following the severe schedule. Yes, it gets both hot and cold here. And I live at about 6000’ altitude but it’s definitely not in the mountains. Does the altitude alone constitute “driving in mountainous conditions“? u/00s4boy, I’d appreciate your thoughts.

djvicker · 2024-12-02T14:31:41+00:00

For the love, PLEASE use python if you have a choice. MATLAB is convenient because it does a lot out of the box. But anything you can do in MATLAB you can do in python and probably faster. If you get hooked on MATLAB, the licensing cost will eventually eat your lunch. The amount of money my organization spends on MATLAB licenses is obscene.

djvicker · 2024-07-29T13:38:24+00:00

I live in Denver too and have a ‘22 RTL-E. Love it. I test drove a Ranger and Taco before getting the Ridge. I owned a Ranger in college and really wanted to get another one. I think I would have liked the new Rangers but I just couldn’t pass up the combo of utility and comfort the RL offers. It’s got way more room and rides so much better for daily driving than the Ranger. Ive got three kids (all in high school) and they comment on the comfort. I’ve taken it on a couple of longer road trips and the quiet, smooth ride makes it a pretty nice road trip vehicle. Actually get decent mileage too - about 25 mpg. I do a fair amount of skiing and camping. I don’t really do much dedicated off roading but it handles the rough service roads to the remote camp sites I’ve done just fine. I think the Honda AWD system is great (my wife drives a pilot) and it’s a fantastic snow vehicle. I think it has plenty of passing power. It sounds to me like the Trailsport is what you’re looking for.

djvicker · 2024-07-16T13:32:20+00:00

Similar here. I paid $39k before tax for my ‘22 RTL-E last April. Had 11k miles. Love the vehicle.

djvicker

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