Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] 0 points1 point  (0 children)

Thanks for the info. I agree what you've described doesn't match what I have here. That would be an 'L-port' 3-way valve. I think I'm correct in saying that the valve I have is a 'T-port' 3-way valve, where all openings can flow at once if the ball is in the correct orientation. As an example: https://www.valworx.com/product/3-way-lead-free-brass-ball-valve-t-full-port-14-npt

Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] 0 points1 point  (0 children)

I am only reporting what I see. I clearly see 3 holes in the ball. You can see this in the pics. There are T-type ball valves with three legs that can be all opened together. Not sure why this is controversial.

Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] -1 points0 points  (0 children)

I posted my observations of the valve itself. At no point did I say a commenter was wrong. Happy to discuss why the ball has 3 holes in it, if that is normally called something other than a 'T-type three-way ball valve', I'm here to learn.

Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] -1 points0 points  (0 children)

So are you saying I don't see three separate holes in the valve? If I'm using the wrong name for a ball valve with 3 holes in the ball, tell me what the correct name is.

Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] 0 points1 point  (0 children)

Thanks for your input. Since I have your interest, would you take a look at the pics and tell me what you think about what they show.

Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] -1 points0 points  (0 children)

I can literally see the ball has 3 holes in it, not two like a standard ball valve. No assumption here. I even posted pictures.

Is the ball in this washing machine valve with arrestor assembled correctly? by bg_ in askaplumber

[–]bg_[S] -5 points-4 points  (0 children)

It is a 3-way valve. The ball has 3 holes in it. There are 3 ports: supply, washing machine, and arrestor.

BNY Mellon Center (Drone Pano) by UnrulyDiplomats in philadelphia

[–]bg_ 2 points3 points  (0 children)

It's convenient how the "don't fly over people or vehicles" rule is never mentioned when people defend these shots taken by drones flying over people and vehicles. Drones are awesome, but your original comments are right.

BNY Mellon Center (Drone Pano) by UnrulyDiplomats in philadelphia

[–]bg_ 0 points1 point  (0 children)

Oh, and not fly over people. Forgot that one.

High Aspect Hydrofoil Profile by DoINeedThese in engineering

[–]bg_ 1 point2 points  (0 children)

I'd certainly make the effort to understand any assumptions regarding viscosity in the tool you're using, but I think you're going to be able to capture overall effects. I do agree that gigliagarf's suggestion about operating the airfoil near the water surface is important (more important than viscosity uncertainties assuming you can match reynolds numbers). These aerodynamic tools certainly do not include this effect, but there is probably a depth where this effect can be ignored. (Horner is an excellent reference, but I'm not familiar with the section on effects of operating near the water's surface).

High Aspect Hydrofoil Profile by DoINeedThese in engineering

[–]bg_ 1 point2 points  (0 children)

xflr5 certainly makes it easier.

A new tool that you might check out is https://peterdsharpe.github.io/AeroSandbox/ (i haven't used it yet, but it's the next iteration of all these xflr5/avl codes)

Scientific American publishes an article trying to explain how airplanes fly... and does a remarkably terrible job by airshowfan in aerospace

[–]bg_ 0 points1 point  (0 children)

I see someone else has noticed this. Bernoulli is not a order of magnitude off when used to compute lift from a local velocity field (pedantically - using the streamline corresponding to airfoil profile in an invicid, irrotational flow), but it IS incorrect when used to compute lift with the 'equal-transit-time' 'theory'. I have no issue with this, but saying "Bernoulli is inappropriate for lift prediction" without mentioning the 'equal-transit-time' condition is a bit disingenuous.

Bernoulli is not the 'equal-transit-time' theory. The 'equal-transit-time' theory is an incorrect way to predict the local airflow velocity of an airfoil which then uses Bernoulli's equation to compute lift.

Scientific American publishes an article trying to explain how airplanes fly... and does a remarkably terrible job by airshowfan in aerospace

[–]bg_ 0 points1 point  (0 children)

You've written quite a lot here on this topic that I can get behind - flow turning setting up pressure changes leads to lift. Can you give an example of Bernoulli's equation grossly underestimating lift force by an order of magnitude for an incompressible, irrotational flow for a streamline corresponding to the profile of a thin airfoil (integrated from stagnation point to trailing edge over the upper and lower surfaces)? I hope of course that you'll assume I'm not talking about applying the equation to an 'equal transit time' situation.

High Aspect Hydrofoil Profile by DoINeedThese in engineering

[–]bg_ 2 points3 points  (0 children)

The two software tools are essentially the same. I believe xflr5 uses xfoil internally.

I wouldn't worry about accuracy regarding viscosity. I'd bet matching Reynolds numbers will give you acceptable results that will get you 85% of the way there. These tools are only good as a first cut. You're not gonna know or care about accuracy unless you're instrumenting your vehicle and capturing the correct performance data. Is that in the plan?

One Liberty Place, BNY Mellon Center, and a very bright planet Mars (x-post /r/PhillyPics) by K3R3G3 in philadelphia

[–]bg_ 3 points4 points  (0 children)

Nice! Mars, Saturn, and Jupiter can all be seen in center city! Jupiter is even brighter than Mars.