What is Helicopter: Definition and 205 Discussions
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL (Vertical TakeOff and Landing) aircraft cannot perform.
In 1942 the Sikorsky R-4 became the first helicopter to reach full-scale production.Although most earlier designs used more than one main rotor, the configuration of a single main rotor (monocopter) accompanied by a vertical anti-torque tail rotor has become the most common helicopter configuration. Twin-main rotor helicopters (bicopters), in either tandem or transverse rotors configurations, are also in use due to their greater payload capacity than the monorotor design. Coaxial-rotor helicopters, tiltrotor aircraft, and compound helicopters are all flying today. Quadrotor helicopters (quadcopters) were pioneered as early as 1907 in France, and other types of multicopters have been developed for specialized applications such as drones.
Summary: Have a hovering craft powered by a jet engine.
Instead of helicopter blades have a vertical jet engine embedded in the craft. Steer via thrust vectoring.
The angular momentum of the jet engine might not provide enough stability but surely there is some way to get that.
ok this is out of an old textbook and possibly already posted here so..
A movie stunt woman drops from a helicopter that is 30.0 m above the ground and moving with a constant velocity whose components are 10.0 m/s upward and 15.0 m/s horizontal and toward the south. Ignore air resistance.
[a.]...
Forces:
Box--> W(weight) and T(tension)
Rope-->T1(reaction of T) and T2(because of the helicopter)
So first i calculated Weight:
W=mg=400*10=4000N
In order to find the acceleration i should use Newton's 2nd law so:
(Box) : T - W = ma
T - 4000=400a
The problem is with the rope...
Hello again everybody.
Encountered another challenge with the helicopter game we've been writing.
For sake of simplicity, let's consider this to be a one-dimensional problem.
I have a helicopter traveling at speed V and an arbitrary pitch angle A.
The acceleration of the helicopter is defined...
Solution 1:
Force on air = Force on helicopter.
##F = \frac {dp} {dt} = v \frac {dm} {dt} = v^2 \rho A##
##P = Fv = \rho A v^3##
Solution 2:
Power from helicopter converted to rate of kinetic energy increase of air
##P = \frac {dE} {dt} = \frac {1} {2} v^2 \frac {dm} {dt} = \frac 1 2 \rho A...
Hello everyone!
I am currently developing a thesi to become an aeronautical engineer.
I am trying to reproduce the NASA report "a mathematical model of a single main rotor helicopter for piloted simulation".
I already built a simulink model but i am having a bit of trouble looking at the...
My thinking was that the power produced by a falling object is P=Fv=(-mg)(-gt)=mg^2t. So it depends on t, ie the "counter power" must also depend on t if it is to balance it, right? But author's solution is a constant. I know I am making a mistake somewhere.
Note: Apologies for the lack of...
Helicopter lift weight of 500kg ,weight is connect with load cell to meassure tension.
Neglect aerodynamic drag..
If helicopter accelarate up ,tension is rope is greater than 500kg.
If helicpter accelarate down ,tension is rope is less than 500kg.
If helicopter fly up with constant speed...
We have 2 forces affecting the rope: 1. Gravitational force of the body ##=mg## and 2. Force of air = Force of drag= ##F_{AIR}##.
The length of the rope is shortening with the velocity ##v_k##.
So to figure out the angle ##\theta## I wrote:
##R##= force of rope
##R_x = F_{AIR}##
##R_y = mg##...
Why does a helicopter blades operates in an advancing direction while the other, the retreating blades travels backwards? That is, what would happen to the helicopter if the retreating blades were to travel forward like their advancing blades counterparts?
I started with calculating the Ep and Ek of the helicopter and got this:
Epi = 490m Eki= (1/2)(400m)
Epf = 12740m Ekf = (1/2)(1681m)
I don't really know where to go from there. Do the unknown mass variables cancel out? I'm lost!
When a helicopter float motionless the work done on it is zero.But why does it still consume energy?A similar question is why when we hold still a weight, we must consume energy(we feel fatigue)?
I have always been fascinated with helicopters and it was the tv series "Airwolf" that started it off. In the show, it was acknowledged that Airwolf is the only helicopter that can fly at supersonic speeds. Granted, I'm no physicist, but I do know it is impossible for a helicopter to fly at...
Homework Statement
This is not my homework question, I was asked to help with it, but I've been out of the engineering field for many years now. Here's the question:
Starting from rest, a 2500 kg helicopter accelerates straight up at a constant 1.7 m/s2. What is the helicopter's height at the...
Hey everyone,I am trying to make a helicopter using an AVR or ARDUINO BOARD I wanted to know how do I calculate the force required to lift the helicopter.Can anyone also help me how much revolutions per minute(r.p.m) should the fans generate.I am planning to use two fans.
Hey all,
This is clearly a very simple question but for some reason my roommate and I just can't agree on this.
The scenario is as follows: There is a helicopter sitting on a scale. The helicopter weighs 700kg and thus has 700*g = 6867 N of force acting on it by gravity. In order to fly the...
Hi,
I had a thought recently which gave rise to a rather interesting query. A helicopter works and is able to fly due to Newton's third law of motion. The propellers rotate at a high speed and exert a force on the air beneath them. By N3L, the air therefore exerts an upwards force on the...
Hello Folks
I'd like to know if anyone of you guys know how to calculate the gforces in a glider (in this case helicopter) during maximum performance acceleration? Tonight I had a very serious discousion with a relative of mine who doubt that it's possible to accelerate from 0 to 140 kts within...
Homework Statement
A Chinook helicopter’s rotor blades and hub have a top speed of 300 revs/min and a combined mass of 300 kg.
On a maintenance test the blade assembly is allowed to stop without applying the brake, in this condition the blades take 48 seconds to come to a standstill. The...
My question may be very simple for most of you but it's giving me great difficulty and your help would be greatly appreciated! So a helicopter with a counter clockwise rotation rotor will want to turn its nose in the opposite direction because of torque effect. This demonstrated Newton's third...
I was talking to my Physics teacher about this at lunch.
If I was to have an rc Helicopter which i had hovering perfecting (if only i had the skill) on a train at rest. What would happen in terms of the position of the helicopter as the train accelerated? Would is stay at the same point in...
Homework Statement
helicopter is flying in air it goes A,B,C,D points
which are distributed in square
and helicopter goes one circle in 4 hours
if wind is blowing in direction from A to D
then the whole circle is flown in 3 hours
question: how does it takes to fly from A to C if wind blows in...
I understand a helicopter in spin would mean a stabilizer is gone and the helicopter cannot maintain its stable altitude. However, I've noticed that helicopters have a tendency not to dip in free fall. I mention that bc I am curious as to what force is at play when objects and people (sorry...
Airwolf (from the T.V show Airwolf) is a Mach 1+ helicopter capable of reaching speeds up to Mach 2. For it's time, it's weapons system was pretty farfetched (had fourteen weapons systems overall, including chaffe and flares) at it's time.
I'm well aware of the limits of regular helicopters'...
Does the weight of a propeller have any effect on the thrust provided? For example, if there are are two propellers of the same size same speed but different weight, would the one with more weight have a greater or lesser thrust? also would effect do the number of blades(faces) have on the way a...
hi,
i am an aeronautical engineer student in need of some ideas for my groups mechanical design project. our project is to design a helicopter winch/hoist that meets the following requirements:
1. is atleast 150ft long
2. max 350kg load at a rate of 3ft/sec
3. (deeper into design) has a safety...
Hi Guys!
I'm doing a conceptual performance calculation and analysis on co-axial rotor UAV helicopter on hover. However, I'm having conflicting results and if anyone can help me, it would be very great.
The design constant of the helicopter are as follows:
MTOW = 20 kg
κ = 1.15 (Induced Power...
The question is:
The main rotor blades of a helicopter sweep out an area of radius 4.0m and push air downards with a speed of 15ms^(-1) away from the blades.
By tilting forwards 20 degrees, the helicopter stops rising and starts to accelerate horizontally at 3.57ms^(-2). The density of air is...
Homework Statement
A helicopter is initially moving at 9 m/s to the left. It then accelerates at 4 m/s^2 to the right for 2s. How far does it travel during the 2 s.
answers:
26 m to the right
17m to the right
10m to the left
5 m to the left
1 m to the left
If you don't want to give me the...
Homework Statement
A helicopter is hovering at a height of 10 meters. It weighs 6230 kg and the diameter of the rotos is 14.6 m. What is the speed of the air that the rotor is pushing down?
Homework Equations
How am I supposed to solve this problem?
The Attempt at a Solution
I'll...
I saw random question somewhere on the internet a couple of weeks ago and it got me really thinking about it.
Supposedly you got a remote control miniature toy helicopter hovering inside a bullet train, if the bullet train suddenly started and accelerated to 200km/hr in 3.5 sec, will the toy...
Homework Statement
A 15000-kg helicopter is lowering a 4000-kg truck by a cable of fixed length. The truck, helicopter, and cable are descending at 15.0 m/s and must be slowed to 5.00 m/s in the next 50.0 m of descent to prevent damaging the truck. Assume a constant rate of slowing.
Determine...
Heya everybody,
I am trying to write a code that will make a toy helicopter to hover. I have cameras that are constantly tracking it, reporting at real time about it's position and angles.
I have control on the yaw (Z axis rotatio), pitch (forward/backward movement), and rotors speed.
I have...
The direction of the torques in the following working will be found using: \vec{\tau} = \vec{r} \times \vec{F}.
When viewed from above, the counterclockwise rotation of the blades produces a torque out of the page:
As the angular momentum (right-hand corkscrew rule) is also out of the page...
Hi everybody,
I am a native of Bhutan and have been always contemplating on building a RC helicopter for myself. In this regard,I have studied helicopter aerodynamics and want to swing into action.
The momentum theory seems a bit easy to comprehend and perform calculations there. But I'm unsure...
Homework Statement
During a rescue operation, a 5200-kg helicopter hovers above a fixed point. The helicopter blades send air downward with a speed of 70m/s .
What mass of air must pass through the blades every second to produce enough thrust for the helicopter to hover?
Homework Equations
ΣF...
A helicopter on a flood relief mission flying horizontally with a speed vo at an altitude H, has to drop a food packet for victims standing on the ground. At what 'distance from the victims should the food packet be dropped'?the victims are standing in the vertical plane of the helicopter.
In...
1. A helicopter starts from rest on the ground and starts accelerating uniformly upward. After 30 seconds a flare was fired horizontally. An observer on the ground measured the time the flare reaches the ground to be 10 seconds calculate A) acceleration of helicopter B) hight flare was fired C)...
Homework Statement
The height of a helicopter above the ground is given by h = 3.30t3, where h is in meters and t is in seconds. After 1.80 s, the helicopter releases a small mailbag. Assume the upward direction is positive and the downward direction is negative.
Already solved for Initial...
Homework Statement
A helicopter is hovering in a steady cross wind at a gross weight of 3,000lb. The helicopter has 275 hp delivered to the main rotor shaft. The tail rotor radius is 2.3 ft and has an induced power factor of 1.15. The tail rotor is located 15.3 ft away from the main rotor...
Homework Statement
A helicopter is hovering 10m above the ground, weighs 6230kg and the rotors are 14,6m in diameter. Which speed does the air have that the rotors are pushing down?
The Attempt at a Solution
i really have no idea where to begin but the chapter has to do with impulse so i...
Holla peeps,in the nearest future I hope to make a rc helicopter. I've done a series of researches and so far things are falling into place but I've just hit a hard rock. All model Rc I've seen are either made of aluminum, plastic or panel boards so am wondering what about balsa wood? Its light...
Hello guys, I have a project I intend to embark on,actually it a helicopter,but I still can't figure out the best type of motor to power the blades of my design. I need something light,small and POWERFUL. I look forward to your contribution.
Thanks in advance.
Hello everybody!
Let me share one of my ideas with you!
This is a modified helicopter. It has raft instead of wheels. Its screw axis can tilt. So may be this machine can both fly and travel on the water surface.
Please comment.