Engineering

Hello I have to make a design for a concentric heat exchanger . The cold water (in the shell) flow rate (1.2L/min) , inltet temp. (25 C) and outlet temp.(40 C) is given. For the hot water (in the tube) the inlte temp.(70) is given and the outlet temp. should not exceed a cretin value (55 C). I also have a correlation between Re and the over all heat transfer coefficient (U) for the hot water and another one between the flow rate and U also for the hot water which I obtained form an experiment. I started by calculating the heat absorbed by the cold water Qc but I can't equal it to the heat emitted by the hot water Qh, the instructor told me to use the mean tempe…

This is so cool I had to link it.

I was wondering what kinds of things would be required for an underwater city such as dimensions maximum feasible depth maximum feasible height minimum size etc and what kind of general problems would need to be eliminated and possible solutions. ps. I mean this a beginning of a general discussion so if you have any ideas please share even if they don't address these specific items

Distillation sets today are far too expensive. So, I'm going to build my own. Here's the ideas I have so far: -The retort will be made from a flower bulb (with the long glass part bent sideways and a glass entry tube inserted by heating a copper pipe of the same size, passing it through, and 'welding' the tube on. -The condenser will be made of a glass tube (coiled if at all possible) inside a cut-open, clear wine bottle that has had two holes melted into it with entry and exit points for water flow, which can be hooked up to a garden hose. Is there any way to improve on this? I'm looking for cost efficiency and product efficiency (though not to the extent that I'd pay…

I can't believe people who are this amazing are real. I knew about famous people with prosthetic limbs like Terry Fox, but these people are closer to the likes of Robocop and Luke Skywalker: So, if you guys were going to have cybernetics, what type of implants would you rather get?

I'm currently reading a novel (Sword of Truth - Book 6: Faith of the Fallen, by Terry Goodkind) in which an army utilizes glass dust as a weapon of war against an army vastly larger than theirs. Using only about two buckets worth of powdered glass, they release the dust into the wind at the opposing army, and ultimately it results in the death, blindness, or incapacitation of well over a hundred thousand enemy troops, whether by blinding them (permanently) on the field of battle and having them accidentally kill one another, destroying their lungs and respiratory tract, or causing serious infections therein. I was just wondering whether there was any plausibility to …

is it possible to make plasma jet engine or even plasma PD engine?

I have an 8-ohm, 0.5 watt speaker that is the perfect size for a project I am attempting. Is it possible to hook this up to an mp3, ipod, or Arduino Uno?

Hello i am working on a project and was wondering if my setup would work to test different induction coils. Parts I'm thinking about using is listed below: Input 120v 60hz -to- 120v VFD 230v 3 phase out -to- Ac contractor -To- (will test many kinds) Also what wire works best?-to- load Click on links to see part.. If I need different parts (so they all work together) please let me know. outcome is to have a set up with best range of frequency and voltage for around 300$ also to have coils make strong flux If you have any better ideas please let me know source will always be 120v wall outlet Well thanks for reading and possibly your help

For an assignment at school I need todesign an extrusion machine for a thick-walled PVC pipe with an SDR of 6. Isthis makeable? Eva

This is my first time posting here so if this is the wrong forum, I apologize in advance. I've been doing some web browsing and can't find much information on this idea I have been tossing around in my head and thought this might be a good place to ask about it. The idea. Static electricity induced perptual motion generator. I really don't have any idea if anything like this would be possible and if it would if static electricity could produce enough energy to be worth it. The basic idea would be that this generator would have an internal battery for start up and storing a base amount of energy so that it can keep running. The spinning of the device could produce s…

Ok, so, I'm presuming everyone is familiar with space elevators, as they've been discussed here plenty of times, so I thought I'd pose a special challenge. Imagine we have all the parts - we have the ground station, the satellite, the elevator, and the super-strong cable. How do you put it all together?

Hello everyone, I have a problem and I really don't know what kind of mathematical method should I apply to solve or model my problem. I would be thankful If anyone can give me some answer or help. Suppose we have more than one option to select a set of numbers. like A={a1,a2,a3,..an} and B={b1,b2,b3,..,bn} (number of members in each set is equal to n) each ai or bi is an integer value. We also have a threshold value lets say "TH". If we choose Option A, the new value of set A becomes A={a1+1,a2+1,....an+1} and also same case for B or any other options. Each round we have options, my question is that which option every time we must select to increase the num…

Hey guys. I'm currently finishing up a lab report on fatigue testing and I was wondering if anyone has any ideas on sources of experimental error? I'm assuming it'll probably come down to calibration but any insights would be appreciated. Cheers!

What are the latest ways to reduce the weight of aircraft, cars and ships? Are we talking new metal alloys or engineering practice?

A Darrieus windmill is meant to spin a generator at its base; where its windings 'cut' magnetic lines to generate electricity. Cutting stronger or more lines of force can produce more power, and the wind force should be capable of keeping it up to a speed in order to produce a decent generation. http://upload.wikimedia.org/wikipedia/commons/3/3c/Darrieus-windmill.jpg But, if the blades were actually made a winding preserving its aerodynamics, and no generator at its base but slip rings; the magnetic lines being 'cut' would be the earth field. Weak but massive, the area being 'cut' would be comparatively huge. Finer wire wound would yield more voltage because of n…

Does cold rolling effect the crystal structure of a material?

How does one slow down the speed of a wind turbine to follow the maximum power point? I have modelled one and the speed is controlled but now that I think of it I dont actually know what the lads n lassies actually do on site to slow one down. I get that the blade pitch can be controlled and that of course that would just have actuators to turn the blades. But what do they do for speed control? just use break pads to slow it down? Can you use the generator to slow resist torque/speed? or even can one use the generator to speed up the wind turbine if it travels too slow. My model didnt need to go into that detail so I just have the torque being influenced to show that the …

I am in the process of design of an ultralight plane for which I only have some of the skills needed. My plane will have a 30 foot one piece high wing with a chord of 6 feet and maximum thickness of 9 inches. It will take-off at about 25 - 27 mph and have a maximum straight level speed of 63 - 64 mph. Weight is a prime concern but drag is not. I believe that it would be lighter to use the leading edge "D" box spar and the rear spar that the flaps will hinge on as the load elements and attach the wing to the top of the fusalage and with struts at some length of the span for twist prevention and longtitudinal stability. Using 600 - 650 gross weight and a 6 g load factor …

I would like to find the engine power/ engine size (in cc) required to lift a helicopter that weights 25 to 30 Kg. Can someone please provide me some calculation? Although the question is vague with not much information I would really appreciate some basic equations to calculation the required engine capacity/power.<br style="font-family: Verdana, Tahoma, Calibri, Geneva; font-size: 13px; background-color: rgb(227, 227, 227); "><br style="font-family: Verdana, Tahoma, Calibri, Geneva; font-size: 13px; background-color: rgb(227, 227, 227); ">Regards

Why does the aerodynamic moment on the aerofoil not change with the angle of attack of the aerofoil? What’s the magic behind it? Does every flying surface have an aerodynamic centre where the aerodynamic moment is independent of its angle of attack?

I'm a newbie here and it has been a long time since I did complex science and I would be grateful for any help and expertise on my problem. I am looking to build a wood burning pizza oven in the middle of no where with no services/water/etectricity etc and hope to use it to also heat some water. My design basically is to sandwich a 10m coil of 10mm diameter copper pipe in the floor - sandwiched between two layers of firebricks. I have looked elsewhere on the net and coiling a copper tube either inside the oven or within the walls of the oven doesnt seem the best idea due to the problems of direct heat on a copper pipe, corrosion and oxidisation etc. I think that s…

I want to control AC devices using Arduino board. Would like to know how many devices can be controlled simultaneously using a single Arduino Uno (or) Arduino Mega 2650 Since I am not a electronics guy, I am not able to understand the digital and analog pins info and hence would like to know the answer for my above query Regards

Researchers at the Amsterdam University use time-resolved Raman spectroscopy to image objects embedded in non-transparent materials. They target explosives hidden in clothes or luggage (an obsession these days). Time-resolution (read: short time) allows to discriminate at the detector between light diffused by the non-transparent material and by the embedded target, whose signal is fainter but strikes the detector from a different distance hence at a different time. Raman effect, as it scatters light back at a different wavelength not produced by the surrounding medium, allows further discrimination. Under "non-transparent" I expect things like cloth or leather …

I want to know the significance of the number "230" for the general household electric supply. Why "230" why not anything else?????