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Time for Will to do a tear down ;-)

So Cd is not drag, Cd times area times dynamic pressure is drag. So one published value of the Cd of the Mazda Miata is 0.38, and one for the VW Caravelle ( the current van) is 0.37. So the Miata has a very slightly higher Cd, but look at them from the front and its clear the Caravelle has over...

OM effin G. Why in my day it was uphill both ways in deep snow in July! As a fellow old fart, would you all get over yourselves. I am a 60 year old engineer, I'm a grey beard, and once upon a time I was the wet behind the ears recent grad, and now I'm working with my 3rd generation of recent...

Enough. As an engineer with a lot of science education, the idea that that turd is more credible than my peers is an insult and just plain stupid. The OP asked about the personal economics of solar. I suppose you yahoos are going to build your own PV cells? Oh wait SCIENCE did that for you...

I would love for Victron to add an MPPT to the Mulitplus II - 12V so I could have a true AIO for a 12V 50 Amp RV solution at 3000 W

So when you were a kid you could buy a car for less than that camera. Nowadays anything that runs is at least $2500. When you were a kid, you could maintain your car yourself. Nowadays, not so much. When you were a kid you could slide on car insurance. Nowadays not so much. Jobs have gone...

Okayyy, Been doing CFD for 38 years. Be Careful. Even if you use the 3D version of this tool, if you dont really understand the inherent fluid dynamics you can get in trouble. That said, thats a clever little tool. You can certainly use it to evaluate a fairing, even a 2D analysis on the...

So Quantum physics is hard, thats why I changed my major from Physics to engineering way back when. But... just as I am not qualified to comment on quantum, he is likely not qualified to comment on climate. Einstein sawed the bottom third of a centerboard off of his boat to get into shallower...

Just an aside. I was looking through this thread but did not read every post. This may have already come up. A Kgf is 1 kg (mass) times 9.8 m/s^2 (acceleration) which gives a force of 9.8 newtons. which is 2.2 lbf So 300kgf is 661 lbf, divided between four bolts/ rods. So that gives a total of...

Actually, I just read that Savanah and New Orleans are trying to get ships to go there. Less backed up perhaps? Oh and I am old enough to remember that when you flew into LA the sky turned this nasty dodge dart brown color. Its still pretty hazy but nowhere near as bad as it was. Those rules...

What in the wide wide world of sports does that have to do with the price of tea in China. Is gun ownership some sort of weird twisted filter for manliness or patriotism for you? Do you own a radiation heat transfer book?

So, who hasn't worked with a hot lead on occasion? If this was some male redneck we would just all shake our heads and go oh well. But let a pretty girl do something sketchy and we get all excited. Not a great job, but whats really wrong with the end product given the loads?

So with low speed flow like this the boundaries need to be very very very far away, and should be a non-reflective or at least only slightly reflective condition. That upper boundary is really a wall, should be pressure or better yet a freestream, ie has the same velocity as the inflow...

So my own experience with solar here in the Northeast has been quite positive. I have displaced 80% of my electricity usage. Certainly it would have been more expensive without the tax credits. But if someone that lives were there is a true winter can do this well with solar (16 360W lg panels )...

So my raw cost of 6500 watts installed was 22K (and that included a chunk of re-roofing) That was $3.38 a watt. High but not too outrageous. With Fed and State (NY) tax credits, that came down to around 10K or $1.54 / watt. My payback (at least at current rates) will be around 10 years. So with...

So this is the difference between an engineered solution and a prescribed solution. The prescribed solution is one that is very conservative, and can be used without any sort of engineering verification. Thus these types of code "requirements" are generally just accepted. You could have hired a...

OK, I'll try again. Every engineering problem NO MATTER HOW LARGE, is an integration of a lot of smaller problems. Thus much is done with integral methods. The fundamental physics are actually quite simple. Though the math is not trivial. How does radiation pass through a gas?. How much goes...

Poverty is a choice? Yeah.. NOT. The unwise choices we make at age 8 should be mitigated by responsible adults. Dont play with fire springs to mind. That goes for stupid choices at 12 through 112. But if you are born to poor, uneducated parents, you are likely to also be poor and uneducated...

Good God! I had one of those! I had blocked it out!

Someone check my math: A basic calc shows that at 75% state of discharge you would have 7,056 watt hours if there were no conversion losses and you ran to 100% depth of discharge. A 100 watt load would drain that battery bank in 7 hours. Between losses, standby load on the inverter and likely a...

So plan D. Reamed out the positive terminal on the shunt to 1/2" and bolted the shut-off directly too it. Now I have a nice run with a single 4/0 wire.

The key is to have a good thermal mass, that grabs that solar. Then we get to use... the greenhouse effect ;-). If you size the mass, window appropriately, have glazing specific to the purpose ( which may be hard to find now). You can keep at least 50% of what you gathered. The key is to get...

Just an update, the 20 amp DC/DC, with the 10amp current limit switched on has been operational for well over a year now. Several longish hauls where I had no opportunity to plug in to shore power or run the generator. Even that measly 10 amps was enough to add a slight charge to the 400ah...

So look, Doing research is not reading papers. Doing research is what climatologists do when the sample the air trapped in ice cores. Doing research is what climatologists do when they count tree rings, sample material in earth cores, etc etc. What any of us do on the internet is not research...

WOW! Just visited this thread after a long absence. If global warming isn't real how come you cant ice boat on the great south bay anymore? Now Bicker!