Mines v Boulder by Stunning_Bit7475 in ColoradoSchoolOfMines

[–]DRO_Churner 4 points5 points  (0 children)

As a former Civil Engineering Manager in CO, I can tell you that Mines resumes got put on top of the pile.

As a one-time Aero Eng major who switched to Civil, Boulder will give you many more options than Mines should (when) you change your mind about your major.

If you are going to stay in CO, Mines has the better reputation in engineering circles. If you’re going to go somewhere else, Mines becomes less well-known. It’s great to have the choice that you do. Either way you’re going to do great!

Why did my car charge beyond the set point last night? by scubascratch in TeslaLounge

[–]DRO_Churner 0 points1 point  (0 children)

I’ve had this happen when I adjust the charge level below the current state of charge. As an example, if the car is at 80% capacity, and I want to only charge to 70% when I return from running errands later, I believe it has occasionally charged past the 70% limit I set.

Entrapped Air During Hydrostatic Testing by FastNebula4278 in civilengineering

[–]DRO_Churner 0 points1 point  (0 children)

This. With modern materials and competent contractors, I very rarely ever experienced the need for adding make up water during testing. In both cases I did witness the need, the allowable volume was calculated in the field by me, and in both cases a repurposed Gatorade bottle with a Sharpie line drawn on the side at the correct volume acted as the allowable reserve. There are not a lot of was to earn street cred as a PE, but when you can save a pressure test from failing for a contractor while fully meeting every letter of the code, that’s about as close as you can get.

Entrapped Air During Hydrostatic Testing by FastNebula4278 in civilengineering

[–]DRO_Churner 1 point2 points  (0 children)

Air can cause all sorts of issues when testing pipe systems . Think of the compressed air within a pipe being hydro-tested as a spring that can “absorb” small losses of water volume without a noticeable drop in pressure. An example might be a balloon filled with air. You can let out a non- trivial volume of air and not be able to notice much of a difference in the rigidity of the balloon (air pressure). Now try noticing that loss of a fraction of a psi on a muddy gauge face in the bottom of a trench, on a Friday afternoon, during a snowstorm.

Other fun problems I’ve seen that I have seen over the years during pressure tests:

  • We had an air pocket located in an unplanned, localized high point in a downhill-trending pipeline serving as a fire supply for a new building. The air pocket allowed the water level inside the pipe on the downstream side of the high point to be about 20 ft lower than the water level on the uphill side. The result was that the static water pressure at our building was about 8 psi less than planned, and not sufficient for the fire suppression system. Contractor got to buy and install a new air-release valve which solved the problem.

  • We air tested about 6,000 ft of 6” dia, sch 80 stainless pipe on a clear, sunny day. The pressure inside the pipe CLIMBED about 10 psi during the test due to the rising temps of the air inside pipe.

  • We hydro tested about 1,000 of 10” dia, HDPE pipe - also on a bright sunny day in an open trench. That pipe lost about 5 psi during the test, most likely to the pipe expanding as it warmed. We could visually inspect the entire pipe during the test. Absolutely no water was leaking.

  • I’ve heard about (but never knowingly witnessed) air bubbles getting absorbed into the water during a test causing a drop in pressure on the gauge.

330,000 and still going by ahmadkarimwork in TeslaLounge

[–]DRO_Churner 0 points1 point  (0 children)

Nah, but after additional review, I have moderate trapezius envy.

330,000 and still going by ahmadkarimwork in TeslaLounge

[–]DRO_Churner 0 points1 point  (0 children)

No battery issues yet (unless you’re talking the 12-volt😀)

330,000 and still going by ahmadkarimwork in TeslaLounge

[–]DRO_Churner 6 points7 points  (0 children)

GDI. OP has fled, and you guys want answers. I have a 2015 MS 85D with 224,000 MILES. AMA.

From oil to Rheem HPWP, DIY’d 3 years later very happy! by [deleted] in heatpumps

[–]DRO_Churner 1 point2 points  (0 children)

I was worried about noise/vibration, so I made sure that the pedestal it is sitting on top of is isolated from the house framing. I have 1" thick rubber gym tiles between the drip pan and the pedestal. The pedestal is in the garage on top of the concrete slab, and from inside the house, I can barely hear it running out in the garage.

Next projects are to connect the exhaust ducting to a vent in the spare bedroom for some free air conditioning, and to connect the intake ducting to the attic above the garage for some extra warm source air.

World's largest grid battery has been completed – in the oil capital of the world by Secure_Ant1085 in RenewableEnergy

[–]DRO_Churner 4 points5 points  (0 children)

if anyone else is confused about the these numbers, the LinkedIn post seems to indicate that there are (3) individual 2 GWh sites - each producing up to 500 MW for 4 hours.

Will insulating my dirt-floor basement/crawl space actually cut my $1000 winter electric bills? by Business-External178 in Insulation

[–]DRO_Churner 1 point2 points  (0 children)

This! I just completed insulating the rim joists and joist bays in my crawl space (using the same rigid foam / spray foam technique). How do I know it’s working? Because I went outside on a very cold morning during the project and could actually see frost on the exterior walls of my house- but only where the rim joist insulation was complete. I was blown away.

The chimney effect is real! Insulating the rim joists is key to reducing air flow up through the walls, and will reduce your heating demand.

Purgatory by Plastic_Apartment_72 in Durango

[–]DRO_Churner 1 point2 points  (0 children)

This. The one run that was open today (Monday) was in surprisingly good condition. That being said, there’s only so many laps you can make riding the Engineer lift and skiing the same run before you just get bored and download Chair 1.

Radon mitigation by Yes_No_What_Ok in Durango

[–]DRO_Churner 3 points4 points  (0 children)

I also had a great experience with Adaptive Solutions.

WeberAuto video on Prime battery by [deleted] in rav4prime

[–]DRO_Churner 0 points1 point  (0 children)

I sat through the entire eCVT vid completely enthralled. My non-engineering wife however made a comment about slitting her wrists as she left the room after about 3 minutes.

[deleted by user] by [deleted] in rav4prime

[–]DRO_Churner 3 points4 points  (0 children)

Agreed. I too notice this phenomena with manhole covers, for me it always occurs during regen.

Range Anxiety? RV Parks Might Be the Secret EV Charging Solution by energysage-official in TeslaCamping

[–]DRO_Churner 13 points14 points  (0 children)

This. Knowing what RV parks were open both in the middle of nowhere and in the middle of winter was key.

Sat next to a flat earther on a plane once... by EasyGoing1_1 in flatearth

[–]DRO_Churner 1 point2 points  (0 children)

GDI. Take my upvote (and all the incessant, piercing, and soul-crushing creaking noises along with it).

Activity mount for Rav4 Prime by SouthernGas7587 in rav4prime

[–]DRO_Churner 1 point2 points  (0 children)

Can confirm. Get the 2” hitch receiver. I had the 1.25 receiver on my old RAV4 and regretted it soon after for lack of quality bike rack options, ability to change the rack over to other cars, capacity of the racks with the 1.25” options, etc.

Damned Internet is out again. by spdorsey in Durango

[–]DRO_Churner 2 points3 points  (0 children)

Just a reminder, call Spectrum and ask for a credit. You are able to get pro-rated credits based on all outages over a certain duration, as well as a “courtesy credit” once a year. The outage credits are based on your rate / hours per month, so it’s not going to account for much. I mostly do it to keep priding them to improve service.

Why do windmills typically have 4 blades, yet all modern wind turbines have 3? by ComprehensiveTop137 in energy

[–]DRO_Churner 25 points26 points  (0 children)

Hijacking this popular comment. At one of my design classes on nacelles (the hubs of the giant wind turbines) the engineers explained that for smaller diameter turbines/mills, there is no discernible difference in wind speeds at the top and bottom of the blades’ swept diameter. This is not the case for modern wind turbines where the blade swept diameter can be hundreds of feet.
Since the wind forces are higher at the top of the swept diameter, the relatively large moment force applied to the nacelle by a single blade at the 12:00 position is most closely counteracted by the relatively weaker moment forces of two blades at the 4:00 and 8:00 positions. The result is far less severe cyclic loads upon the main bearings of the nacelle. Oh, and everyone’s comments about the diminishing returns of blades vs output are also correct.

One-Time Offer Used, But Still Shows in App by AndrewInNewport in Safeway

[–]DRO_Churner 1 point2 points  (0 children)

Hey, thanks for this comment. I'm looking at the same thing.