What is Propeller: Definition and 141 Discussions

A propeller is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral, that, when rotated, exerts linear thrust upon a working fluid, such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis.

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  1. L

    Power output of an anchored propeller

    I have a motore with a propeller anchored to a load cell to measure the lift produced at varying power inputs. This is for a student activity I am running and I wanted to show that though more power in gives more lift there is a point after which efficiencey starts to go down again so I tried to...
  2. A

    Propeller rotating in horizontal plane

    Hello, I have a project whereby I am designing a toy that spins a horizontally positioned propeller, then releases it. After releasing it, the propeller gains height, but moves somewhat away from the operator of the toy. Is the direction of airflow through the propeller vertically? If...
  3. B

    Levitation using earth's magnetic field - electric propeller .

    Levitation using Earth's magnetic field - "electric propeller". I have idea how to levitate using weak Earth's magnetic field. It is something like electric propeller - magnetic field line booster. There is 3 wires (in this case). With no current in wires all is standard, no levitation...
  4. P

    How to improve the efficiency of a propeller?

    Homework Statement One of your friends is building his own airplane. He has received a quotation for a two-bladed propeller with an efficiency of ##\eta = 80\%## . He asks for your advice on whether it is possible to get a higher efficiency - what is your answer? no, the efficiency based on...
  5. karush

    MHB How many radians does the airplane propeller rotate in 190/3 pi seconds?

    OK, want to see if I am using the use of rad properly here the answer seems very small. but 35 degrees isn't much for all the rotations. Answer not in book so hope these are correct.. thanks ahead.
  6. S

    How to Estimate Optimal Propeller Pitch?

    All, Turning to the experts with a boat problem I'm trying to solve. Specifically, I'm in the process of changing the gear reduction of the transmission on my boat and will need to get a new set of propellers with a different pitch. The old set up worked just ok... I tested different...
  7. leviterande

    Will this propeller arrangement have a net force in one direction?

    Hi, I am very sorry if I have posted in the wrong forum, I don't know wether to post in classical physics or aerospace engineering. I have been wondering this theoretical thing a lot lately and I can't figure it out, it should have a simple straight answer though so your help is very...
  8. E

    Fluids Problem - Dimensional analysis, pipe flow, propeller

    Homework Statement I have a tutorial question I have been struggling with. The problem is: The flow through a closed, circular sectioned pipe may be metered by measuring the speed of rotation of a propeller having its axis along the pipe central line. Derive a relation between the volume...
  9. S

    How Can I Calculate The Thrust of a Given Propeller?

    I'd like to know how to calculate the thrust of any given propeller
  10. S

    Propeller Driven Aircraft with Thrust to Weight Ratio Greater than One

    Hello all, this is my first post. I was wondering if any of you could point me in the direction of a source with details on propeller aircraft able to produce a T / W Ratio greater than one. Thank You!
  11. T

    Finding the coefficient of lift of a propeller blade?

    Homework Statement I need to approximate the thrust given by a propeller blade that are plastic and around 10-15cm in diameter but I am not sure what the coefficient of lift (or coefficient of thrust because they are the same thing?) is. For example, a propeller blade may look like this...
  12. D

    How Does a Surface Piercing (Boat) Propeller Work?

    This is a propeller on a boat, that is half in, half out, of the water. They provide more speed on light, fast boats. If you require more information, google "surface drive" or "wave piercing propeller". Companies like Arneson and Seafury manufacture these. Wikipeda has only 3-4 lines on it...
  13. S

    How do I size a hydraulic motor to fit a 12 propeller to move water?

    How do I size a hydraulic motor to fit a 12" propeller to move water? I have a 35 HP diesel motor direct driving a hydraulic pump producing 16 GPM at 2000 psi. The hydraulic pump would be connected with hoses to a water pump inserted in a pipe. I want to design/build a water pump using a...
  14. N

    Propeller - need to calculate the area

    Propeller -- need to calculate the area Hello I am doing a research on different propellers, including how do different propellers ( different mass/size, number of blades ) with different speeds change the rpm and the thrust. However to continue my research and to be able to graph it, I need...
  15. U

    Help finding propeller thrust.

    Hello, I am working on a project regarding truss analysis on a plane and I need to find all the forces acting on the truss in order to produce static equilibrium (note that I have not yet taken fluid mechanics and I wanted a challenge). From what I have found, propeller thrust is: Thrust...
  16. H

    Need Help with Cycloidal Propeller Theory

    Trying to figure out how to model a cycloidal Propeller. Here is the concept I am using. http://www.rexresearch.com/voight/propbew2.gif When the Socket (left side) is on the axis, the propeller blades to the left or right are at 90 degrees. As long as this socket is on the axis the blades...
  17. T

    Formula for Aircraft Propeller Thrust

    I'm trying to understand thrust for a real world application. I found this formula: T= pi / 4 x D(squared) x (v+V1/2) x p x V1 Where: T thrust [N] D propeller diameter [m] v velocity of incoming flow [m/s] V1 additional velocity, acceleration by propeller [m/s] P density of...
  18. A

    Centrifugal twisting moment of a propeller

    I am interested in calculating the centrifugal twisting moment (CTM) of a variable-pitch propeller blade. It's been a long time since I did anything with moments of inertia, so I'm looking for pointers to good info, or direct help if someone here can provide it. Assume there is a propeller with...
  19. O

    A cart driven by a propeller with a constant acceleration

    Homework Statement A cart is driven by a large propeller or fan, which can accelerate or decelerate the cart. The cart starts out at the position x = 0m, with an initial velocity of +4.85m/s and a constant acceleration due to the fan. The direction to the right is positive. The cart reaches a...
  20. L

    Flow over a feathered propeller

    The propeller of a turboprop engine is started with the propeller blades feathered (in-line with the flow): see video: . As the propeller speeds up and reaches idle speed while still feathered, and the incidence onto the blades is very high, does this mean that the flow over the blades is...
  21. J

    Integral? Average Velocity of a Spinning Propeller

    I'm trying to find the average velocity of a spinning propeller. v(r) = RPM C(r) / t ; C(r) = 2πr; t=(1 min) v(r) = RPM 2πr / (1 min) I'm not quite sure what to do next. I need the answer in units of velocity, but if I integrate that last equation, I won't get units of velocity. My rough...
  22. M

    How to calculate quadrotor propeller torque due to aerodynamic drag

    I'd like to know the right formula to calculate torque of a quadrotor propeller (propeller pitch is constant) due to aerodynamic drag in terms of angular velocity ω. For the sake of my simulation I'm assuming `APC 10x4,7` propellers. I'd like to refer to...
  23. E

    Micro wind propeller design

    Hi everyone! I would be so happy if someone could help my little brother and I answer a question for a science project that we have researched ineffectively for hours. We hope to design the most efficient propeller for micro-wind turbine. The purpose of this propeller is to naturally rotate when...
  24. F

    Calculation of Propeller Thrust

    Is there any way to calculate the thrust provided by a propeller, given only the geometry of the propeller and the windspeed. Given: Stationary propeller Wind Speed = 30 m/s Blades = 10 Propeller Geometry: Constant Chord length (γ) Square tip Propeller Pitch at root = α Pitch at...
  25. W

    Quadcopter without propeller (with hidden propeller)

    Hello everyone, First, I'm sorry about my bad english, if something you don't understand correctly, please ask me, so I'll try to explain it. _______ My idea is a quadcopter without propellers, actually the propellers are hidden. This idea comes from this video. It's a "bladeless fan" or an...
  26. V

    Propeller rotation direction question

    How can you tell from a diagram of a ships propeller the direction it is moving ie clockwise or anti-clockwise. Am I correct they don't all move clockwise? What factors determine it?
  27. D

    Hovercraft question regarding propeller and motor

    Hi there i was thinking about trying to build a light hovercraft that can transport one person and I had a few questions about the propellers and motors and how they work. The first question is, is it possible to run a hovercraft with an enclosed fan, for example like that found in a jet ski...
  28. I

    How fast is air blown from a propeller.

    Let's say that we have a simple propeller, which consists only of two flat blades which is inclined at an angle of ∅ with its plane of revolution. Given, the rpm and the length of the blades, is it possible to calculate how fast air is going to be thrown back?
  29. L

    Moment of inertia formula for a propeller

    Is there a moment of inertia formula for a 2 bladed propeller? If you only have the mass and the length of the propeller, I would think a good estimate would be using a rod rotating about the middle. 1/12ml2
  30. K

    Comsol - Balancing of the rotating propeller

    Hi, I am new in comsol. I currently doing a simulation on rotating propeller. I need to obtain vibration magnitude of the rotating prop.. can anyone tell me which type of analysis and how i can get the data? I have been working on this and search over the google for past two week didnt...
  31. mheslep

    Propeller efficiency and energy loss

    Googling for information on the topic leads me to graphs such as this, which suggest that if Beta and advance are optimal efficiency tops out at 85% or so. Some questions: 1) Is the ~15% lost energy converted to heat, or is there some stray kinetic energy in airflow that is somehow unusable as...
  32. A

    Help calculating static thrust for a given engine and propeller

    Hi guys, I need to be able to estimate the thrust that a turboprop propeller produces at sea level static. Say I have an 1100 hp pt6a engine and a 80 percent efficient propeller. I have seen formulas that calculate the thrust but you need to be moving. I want to know the static (your airplane...
  33. C

    Maximum propeller diameter

    Ok I'm trying to work out a few things with propellers but I am struggling to work out if I have got this right. If I have an 1800 shp engine running at about 2000 rpm and I want my aircraft to have a maximum speed of approximately 350 mph what is the maximum diameter I can have the...
  34. K

    Aircraft Propeller Balancing Discussion

    Hi all, May i know anyone here have been involve in aircraft propeller balancing before? i was requested to do test on aircraft propeller static & dynamic balancing using Bruel & Kjaer vibration equipment. May i know anyone have any experience with it and mind to share with me? thanks
  35. C

    Rotor vs Propeller: Know the Difference

    Hey guys, I have always wanted to know the difference between propeller and rotor though they are used for similar applications. I never researched on it until now when I had to write it down as one of my assignments. Any answers will be appreciated and also if anybody can refer me to any books...
  36. D

    Powering Propeller with Pulley

    Hi everyone! I want a string on a pulley to supply the power for the propeller, meaning i pull the string and the force is transformed to the propeller. I was wondering how could i create the system so that i can pull the string time after time and give the propeller more power (keeping...
  37. G

    Hover bike - what is the minimum propeller rpm required?

    Hello, I read this article about someone who made a hover bike prototype from a motorbike and two propellers. Best part is, its classified as Ultralight and doesn't require a license to fly! I can totally see myself building something like that in my back garden! How can I calculate the...
  38. D

    Water flow and propeller speed

    hi everyone! need some help about propellers..say i have a fixed mounted propeller and a flow of water with known velocity runs through it.. what would be the rpm of the propeller??.. i know there a re lots of things and parameters to consider... i need some good references, calculations ,and...
  39. S

    What Are the Best Propeller Design Programs for Airplanes?

    Hey I was wondering if anyone knew of a propeller design program, preferably written in Matlab, but I'd take anything. I am familiar with XFoil, XFLR5, and XPlane, but I don't know of any good propeller design programs. I have read into MPVL, but I'm pretty sure that is just designed for...
  40. N

    Increasing Fuel Efficiency through Propeller Upgrades

    Hello, I am looking into ways to increase the fuel efficiency in a various number and type of ships, with engines running from diesels to steam plants to gas turbines. I was wondering where I might find information on the state of the art practices with propeller design. Specifically...
  41. M

    Angular velocity of an airplane propeller

    Homework Statement An airplane propeller is rotating at 1900 rev/min. Compute the propellers angular velocity. Homework Equations The Attempt at a Solution I know 1rev/min= 2pi/60 rad/s so i multiplies 2pi by 1900 and got my answer to be 3800pi/60 rad/s but idk if that's correct? someone please...
  42. E

    Calculating Thrust in Propeller Engines: Can Anyone Help?

    Can anyone help me? I'm doing a question on aircraft propulsion technology and I'm stuck. The question is: 'If the mass of air through a propeller is 1000 Kg/s, the aircraft's velocity is 100 m/s and the slipstream velocity is 120 m/s, calculate the thrust? Attempt at answer...
  43. H

    Calculating Propulsive Efficiency of an Aircraft Propeller

    An aircraft is flying straight and level at a speed of 150 mph. Its propeller has a diameter of 8 ft and is generating 300 lbf of thrust at an altitude of 3000 ft. What is the propulsive efficiency of the propeller at this operating point? no equations given, but from searching around I've...
  44. S

    Propeller of a ship - construction

    Hi guys I am into construction things, I have learned to construct many things now i am into propellers so can anyone tell me how to construct/ design a simple basic working propeller. How to construct the blades, at what angle, pitch thickness, etc etc... any e-book or site where i can i find...
  45. J

    Rotational Kinematics? Revolutions of a propeller?

    Homework Statement An airplane engine starts from rest; and 2 seconds later, it is rotating with an angular speed of 420 rev/min. If the angular acceleration is constant, how many reovlutions does the propeller undergo during this time? Homework Equations \theta = \omega 0 t +1/2 \alpha...
  46. M

    Calculating Propeller Thrust Using Given Data

    i need to calculate thrust produced by a propeller whilst flying, using the data show below. all equations i have come across require the propeller induced velocity which is not given. things i know; -propeller efficiency -indicated and true airspeed of aircraft -temp. and pressure at...
  47. K

    Propeller Slipstream & Tailplane Instability

    Is the effect that the propeller slipstream (i.e the helix) hits the tailplane causing much instability quite significant such that if u are using a tractor propeller a single rudder won't work creating the need for two rudders away from the slipstream path??
  48. A

    Can a propeller driven aircraft break the sound barrier?

    Hope this is the right place for this question, but it is very inetresting to me so I wanted to ask some experts. Can a propeller driven aircraft break the sound barrier? My answer, no. Any opinions will help Thanks
  49. F

    How can I calculate the pitch of a hovercraft propeller

    How can I calculate the pitch of a hovercraft propeller, what variables do I need? How do I know how many blades must I use to get the ultimate end result?
  50. 3

    Propeller Efficiency Report: What to Include & Refs

    i will make an report about the propeller efficiency can anyone help me and tell me the things i need to put in this report and the references i can use
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