Engineering

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?????

A pre-programmed robot has to be employed for collecting soil samples from agricultural farms. The robot moves along a pre-assigned path to collect samples. For the purpose of navigation, suitable sensors have to be employed. The accuracy of the travelling path from the actual co-ordinates should be less than 0.5 m. Although GPS is the usually employed method for navigation purposes, the accuracy of GPS is between 1 to 10 m (which is very low). Assume the size of farm is between 10 to 20 hectares Please note that this is not a project nor some assignment. I just want to provide some typical scenario Could someone suggest some suitable navigation assistance sys…

I can understand the working mechanism of a 2-way or 3-way electrical switch. However, would like to know if a 2-way or 3-way switching mechanism is possible with a electronic circuit? Also, if it possible with a combination of mechanical switch and electronic circuit (means one of the 2-way switch is a mechanical switch and other switch is an electronic circuit) Regards

So far I have learnt that automation engineers replace man power with machines/robots, does this mean automation engineering is the same thing as robotics engineering? I have done some research and found they done the following: -CNC -CAD/CAM, Design Software such as Solidedge -PLC -What else do they do? I heard they also do electronics, what type of things would they learn? Also, is this more geared towards electrical or mechanical engineering?

I just saw an incredible news story on TV about a car that drives itself. It uses GPS and for "fine-tuning" has a spinning dome on top of the car with lasers scanning the surroundings. It has a nearly perfect image of all sides of the car, simultaneously, which is something humanly impossible. The car steered and accelerated on its' own, at rather high speeds, around an obstacle course, with perfect results. According to the inventor, the driverless car is not far away. It is invented by Sebastian Thrun of Google.

as of right now there really can't be any underwater development in terms of real estate and cities such because transportation would be difficult. standard internal combustion is out for obvious reasons. nuclear is out for a publicly available transportation method for equally obvious reasons so what would be kind of propulsion would work best within the restraints that it has to travel long distances most likely aprox. 200 mi and pressure at whatever depth the destination would be located at presumably at depth no greater than 400 feet. without a recharge/refuel has to be affordable to people who are not necessarily extremely wealthy. and be able to handle wave…

I'm making a small vehicle that has a steam propelled aelopile. THe aelopile spins a propellor. How much steam pressure would be needed to move around a 1kg weight about a meter or two?

What if there is a grenade, that causes little to no damage to its surroundings, but releases a gas that removes the oxygen from the surrounding areas to take away the fires life source? Something firefighters can use without entering a room that is full of fire.. it think it would be amazing to have it, and someone should design one, or even create one. Anyone else think its a good idea?

Hi all, I have power load data for a specified period (about 35 days) , I need to model it using neural networks and then fuzzy logic. for example for the first day: Time Interval Load 9:02:01 183 9:22:14 198 9:42:27 195 10:02:40 198 10:22:53 203 10:43:06 190 11:03:19 184 11:23:32 219 11:43:45 227 12:03:58 232 12:24:11 258 12:44:24 218 13:04:37 213 13:24:50 211 13:45:03 215 14:05:16 233 14:25:29 223 14:45:42 220 15:05:55 232 15:26:08 224 15:46:21 233 16:06:34 236 16:26:47 223 16:47:00 223 17:07:13 223 17:27:26 237 17:47:39 241 18:07:52 262 …

Bit of a weird one, I have terrestrial digital TV though and aerial and booster. I noticed some interference on the TV ('blocking') as i was playing a youtube video. However when I paused the video the interference stopped and I found I could cause or stop interference by pausing or playing the video!! Weird I thought. The signal is not great on this TV channel but it usually OK. I also tried playing a video in VLC player but that caused no interference? Even weirder I tried other youtube videos and they did not seem to cause interference, certainly not anywhere near to he same extent. The video in question was. I even tried another U2 video whic…

How do you know which compacitor to use? Since on the compacitor it is measured in micro-farad, how do you know how much amps or voltages it can store?

How exactly does the message signal get imparted on the carrier spectrum to reach its destination?

I was wondering if it is possible to create a new type of spring or device that stays the same energy output as it's is being compressed? normally when you compress a spring the more one compresses it, the harder it is to compress.

Hey Guys, I've got a question. People who usually created medical devices were electrical engineers end etc.... But now there is a special major in Germany call the new Medical technology, which i am studying now... . Do you guys know how the technical term called in the US for this major? It is not biomedical eng.!!! Does this special major exist in the US??? Thx!! )

If you had to brand a planet use'n only the atmosphere how would u do it? Rephrase:Lets say u had to find out what planets out there had Air but u could not go there u have to send something to the planet that would react forever to an atmosphere and let u know that it has found one with what and how would u do it? By Olala ^.^)/

The concept of carbon capture and storage is something most people are aware of. It refers to a technology used to address problem of CO2 emissions by some the world's largest offenders - namely the fossil fuel industry - by sequestering and storing large amounts of the gas. Over the years, many methods have been developed to help achieve this, all with varying degrees of success, as per the below flow chart: [From here] I'd like the focus of this thread to only be on one of these, specifically metal organic frameworks (MOF's). For those who do not know what these are, the wiki article on them is fairly informative. The major issues in developing a way to capture…