Rotor Definition and 150 Threads

So I was reading about asynchronous motors, and it seems the motor works better when the resistance of the rotor is smaller. This is fairly obvious, because the smaller the resistance, the bigger the inductive currents and therefore more mechanical force is applied on the rotor, thus its doing...

Hello I am making a helicopter flight simulation and I need an answer to this question: when you push the cyclic forward, does this create a torque which will rotate the helicopter. if the answer is yes, please tell me what counteracts this torque and stops the rotation when I return the...

What formula would one use to determine the centrifugal force at the tip of a rotor of 35ft diameter, rotating at 392rpm? Would any other factors be necessary, such as blade thickness, weight, etc? A pilot I work with doesn't believe the weight at the rotor tip would be measured in tons. I...

Homework Statement A rotor ride has a radius of 10 m. The ride is in its experimental phase, so the engineers have decided to use a monkey instead of a person. The mass of the monkey is 30 kg. The sides of the ride are designed so that the maximum friction riders will experience is 0.4*Fn...

Homework Statement I'm having difficulty obtaining an accurate value possibly due to unit conversions. Homework Equations r_m=mdot/(2*pi*U*N) r_m=mean radius, ft mdot=mass flow rate, lbm/s U= blade velocity, ft/s N= RPM The Attempt at a Solution I know that I have to convert Rpm...

Hello! I am creating, or at least attempting to create, a human-powered helicopter. I need an equation to figure out the lift from the rotors. I plan to use four counter-rotating rotors, three blades each, and each blade made of foam, with aluminum ribbing. The blades will be six feet each...

Hi all, I'm currently undergoing a masters of science course in Mechatronics Engineering. One of my core modules is Electrical Components. I'm stuck in understanding one of the key parts in this module. I've been asked to derive the Tangential and Normal forces of the rotor shown below. I've...

In a 3-phase squirrel cage induction machine, why the rotor terminals are short circuited?

This isn't so much a homework question but rather something I need to know in order to design something. I need to know how much a brake rotor will heat up during braking. The force it needs to stop is a 120kg object traveling at 30 mph. I don't know any of the equations necessary to figure...

Homework Statement The rotor of a 3 phase 60hz 8-pole induction motor takes 220w @ 3hz. Find the rotor speed and the rotor copper losses. 2. The attempt at a solution I have found the rotor speed by using the equation slipspeed = fr(120)/P = 3hz(120)/8 = 45 rpm then finding nsync by...

Hello, Out of curiosity I've been trying to mathematically model the forces on a rotor during auto-rotation starting with the basic lift/drag equations used for analyzing basic fixed wing flight (i.e. our beloved L = 0.5*Cl*rho*A*v^2). At first I thought this shouldn't be too hard since it's...

Hi, I'm currently trying to find out how to calculate the torque required to slow a rotor down from a high rotational speed to a low rotational speed. I know the inertia of the rotor, the 2 rotational speeds and the time it needs to take to slow the rotor down. Is there a method or formula...

I know as a fact that excitation (amount of current on the generator rotor) determines the amount of reactive power output from the generator. But why? How does it turning the excitation up or down influence the reactive power output? Thanks.

Overlooking the difficulty in landing such a craft, would a helicopter with the main rotor below the center of mass, differ significantly in stability from normal one with the main rotor above the center of mass?

Video: https://www.youtube.com/watch?v=dBS1NRsYuF8 Pretty cool. You can't beat the sound of a Huey though!

Heyhey, I am currently doing my final year masters project which involves testing rotor blades. I am performing a stress analysis of the blades. I will be using FEA software, but I also need to do some hand calculations. I have been looking for formulas for a while now, but I am unsure which...

My brother bought a http://www.centrix-intl.com/details.asp?productid=4909" RC helicopter. It has a tail rotor which is mounted parallel with the ground and enables the chopper to go forwards or backwards. The helicopter goes backwards great, but it doesn't go forward too well. I would like to...

For Kaolin slurry filter presing we are using progressive cavity pumps.After three months of operation we found that the pumping rate is reduced a lot.Upon investigation we found taht this is because of the abrasion. 150 micron Chromium coating done, still after three months ,this again failed...

Homework Statement Determine the camber angle of a rotor blade for an axial flow turbomachine. Homework Equations Beta1 - Beta2 = Camber angle (theta) The Attempt at a Solution http://img517.imageshack.us/img517/2965/blade.jpg If the camber angle is equal to beta1 minus...

Hello! I need help with this typical quantum problem: I have a quantum rotor in 2 dimensions. And a perturbation along the x direction: Here's the unperturbed Sch equation: -\frac{\hbar^{2}}{2M}\frac{\partial^{2}}{\partial \phi^{2}}\psi(\phi)=E\psi(\phi) And here's the...

Hello Forum, I have a 3 phases DC brushless motor from a Hard Disk Drive, when energize one coil and turning by hand the rotor i can feel 4 steps per rotation, is this means that this motor has 4 poles of north and south? Thank you in advance, Anita

Homework Statement Charged Cylinder has length L and radius a. Charge density increases within the equation rho = rho0(r/a)3 where rho0 is constant and r is distance measured from cylinder´s axis. Outside of the cylinder charge density is zero. a, Calculate the electric field inside and...

Hi, I'm a UT Mech E student about to graduate who's been tooling around with with some helicopter dynamics books for home machined RC contrarotating helicopter fun and I had some questions for any aerospace pros lurking around here. Being ME I know few aerospace guys so I've got some burning...

Hi everyone, I am looking into subject matter to use as my final year project at university. The Tesla Turbine is something that I have recently looked into. I am interested to know the following... In the Tesla Turbine, water is 'injected' and border interactions of the different molecules...

Lets say I will be operating a generator underwater in a "box" sitting on the river floor. Turbine blades will be spinning a rotor attached to said generator, and obviously the turbine blades are exposed to the water and the generator is sealed in the box. I'm having trouble identifying what...

What calculation is the to find the amount a helicopter (or flying device using rotor blades) can lift? I would of thought I would need to take into consideration the RPM of the blades, the size of the blades and maybe the angle. I was hoping there would be some calculation telling me how much...

concerning a rotor with an imbalance, how does the angular velocity of the rotor affect calculations about the size and placement of the correction weight?

How can you calculate the amount of thrust needed by the tail rotor of a helicopter to counter the torque of the main rotor?

Homework Statement The maximum indicued emf in a generator is 205rpm is 43.0V. How fast must the rotor of the generator rotate if it's to generate a maximum inducded emf of 55.0V? Homework Equations E= NBAsinwt The Attempt at a Solution 205r/m*2 (Pi)/ 1rev81min/60s = 21.46rad/s magnet...

Hello folks I've been a little confused - I'm currently designing a rotorcraft but I need to be able to predict the force (or torque) I'd need to tilt the rotor. What I've done is model the rotor as a simple rigid disc. I've attached the diagram below. what sort of behavior would I get during...

Hi, I have a question about synchronous motors. If the DC field winding of a synchronous motor were to be replaced by a low-impedance short-circuited coil and the stator were to be supplied with 3-phase AC, would the rotor spin? If the answer is yes, would the rotor follow the direction of...

I'm trying to find a DC motor with the rotating part on the exterior (the electromagnets and wires attached to the central axis) - something similar to a computer cooling fan or ceiling fan. It must be as powerful as possible for about 2 inches diameter. Any idea where I could find such a thing...

Hey - I am a bike mechanic with a large interrest in physics. I know that a larger disc brake rotor provides a greater braking effectiveness, but how can you mathmatically prove it by using physics formulas? And what formulas would be useD? Any ideas would be highly appriciated!

Hi, This is my first post here, but I've been enjoying the site for some time now. I've run into a snag with an equation I'm trying to develop. Its purpose is to help determine power requirements for radio controlled, model helicopter rotors: P = ( π2 Θ3 Cd ρ A / 2 ) ( R4 - r4 ) P =...

I was thinking about the difference between the appearance of a propeller on a plane and a rotor on a helicopter. What is the consensus?

[SOLVED] geometric algebra: longitude and latitude rotor ordering? Was playing around with what is probably traditionally a spherical trig type problem using geometric algebra (locate satellite position using angle measurements from two well separated points). Origin of the problem was just me...

Homework Statement A model of a helicopter rotor has four blades, each 3.20m in length from the central shaft to the blade tip. The model is rotated in a wind tunnel at 600rev/min. a.) What is the linear speed of the blade in m/s? b.) What is the radial acceleration of the blade expressed as...

Hi, I'm looking to numerically solve the rotational Schrodinger eqn. for a molecule which I'm happy to treat as an internally rigid body. The molecule will be in an external potential, so it's not a free rotor. Does anyone have any advice or references for an easy derivation of the K.E...

All helicopters have two rotors. Some have both rotors on vertical axes but rotating in opposite directions, and the rest have one rotor on a horizontal axis perpendicular to the helicopter body at the tail. Why is a single rotor never used? :frown:

Hello, I am wondering what the best (and simplest) way to secure a rotor disk to a shaft is. I have a 3" diameter Acrylic disk with a 0.375" hole drilled in it to accept a 0.375" diameter steel shaft. What do you all think? Thanks, Jason O

The picture is the rotor that runs in a stator with similar teeth, the stator is aprox 18 inches long and has 21 rows of teeth, if a forign object gets into this mixing head the teeth can bend makeing it imposible to disasemble, anyone have an idea how to straighten bent rotor teeth ...

See the web page: http://www.geocities.com/rolfguthma...ent/patent.html This new patent has the best explanation on the gravity anomaly observed of the experience accomplished by Eng. Russian Eugene Podkletnov in Tampere/Finland in 1996. See the site: Podkletnov's basic article (1995)...

Gyro Rotor Question. Can't figure it out! Need help tonight if possible! I am taking a dynamics class which is reallly difficult. I've been able to solve all of the problems but this one. Can anyone help me by tonight? A rotor mounted in bearings spins about a horizontal axis as shown...

what i mean by this is a basic dipole motor, but with two of them side by side set at different angles. it's kind of hard to explain. but try to think of a tripole motor, but with an extra pole. then keep both of extra poles at different angles than the other two (so maybe 90º apart, or smaller...

having some major issues with this unit, mainly since the homework was assigned and we haven't been lectured on it yet...so it's new to me. anyway, if anyone can help me out with this problem, that'd be awesome. -----A helicopter rotor blade can be considered a long thin rod. If each of the...

The rotor of an electric motor has rotational inertia I am = 2.5*10-3 kg · m2 about its central axis. The motor is used to change the orientation of the space probe in which it is mounted. The motor axis is mounted along the central axis of the probe. The probe has rotational inertia Ip = 8 kg ·...

A model of a helicopter rotor has four blades, each of length 3.90m from the central shaft to the blade tip. The model is rotated in a wind tunnel at a rotational speed of 480rev/min . A.) What is the linear speed of the blade tip? given R= 3.9 T = 480 would it just be V= 2*pi*R/t...

When I took my courses on electrical machines, it always said about cylindrical rotors surrounded by cylindrical stators. Well, I have been thinking about situating the statoric electrical poles conveniently over an sphere surface. One technological application of this would be the next...

Help with problem..."rotor ride" OK I was assigned this homework sheet on Uniform Circular Motion and Law of Universal Gravitation...and there is only one problem I can not get. If you could, please help me. Thanks in advance. Here it is: The "Rotor" ride is the one which presses you...

[SOLVED] rotor rooter and artifical gravity There is a ride in the carnival called the Rotor Rooter in which people stand up with their backs against a curved wall. This wall starts to move swiftly, spinning in a circular motion and then the floor drops out and a person finds themselves not...