Airfoil Definition and 90 Threads

Hi I know that for an airfoil, it's typical to describe stall in terms of angle of attack. I'm wondering, how does Re play a role in flow separation of an airfoil (and for objects in general such as a plate, sphere, or cylinder)? One Wikipedia (http://en.wikipedia.org/wiki/Flow_separation) it...

Does anyone know of any types of research out there that attempts to establish analytical ways to design an airfoil. As far as I understand it right now, when someone wants to design an airplane they grab some premade airfoil shapes and test there design empirically using CFD or a wind tunnel...

In which range of Reynolds numeber is laminar flow for airfoil? Is it Re < 5 x 10^5? How about turbulence case?

what are the equations used for pressure distribution in solid work when analyzing of an airfoil

First post here on pf! I wanted to ask if it's feasible to determine velocities at the top / bottom surface of an airfoil due to the vortex sheet placed on the camber line (due to thin airfoil theory). I'm attempting to do this because the big picture is to determine the Cp distribution...

Consider the production of lift only as the reaction force from displacing a mass of air downwards. No matter the mathematical abstraction (Bernoulli, circulation theory) this Newtonian explanation must hold true. So now imagine a rectangular wing in a wind tunnel where the wing spans the...

I have to analyze this airfoil at 4 degrees: "Consider a wing of span 15 feet. The root chord is 2.381 feet. The tip chord is 0.953 feet. The airfoils used are NACA 65-210 sections, which have a zeo-lift angle of –1.2 degrees. The wing is untwisted." Now I've got a MATLAB code to analyze this...

Does anyone know how to determine the leading-edge radius of an airfoil using just the x y coordinates.

I'm looking to generate a C-grid for an airfoil using Matlab with clustering at the surface and wake region. I've looked at a book called Computational Techniques for Fluid Dynamics Vol. 2 and it does a decent job of explaining it and has a code but the language is in Fortran and I have no...

I have done a wind tunnel experiment on NACA 0015 airfoil for different angle of attack at a fixed velocity. Also calculated Cp, Cl, Cd and Cm for each angle of attack. Now I want to do an error analysis to find uncertainties in Cl,Cd and Cm. Please explain how I'm going to do that? I have...

I need help to determine the angle theta at each point of the surface so that i can apply numerical integration to get the lift and drag using the pressure distribution. How can I define theta?

I'm having a bit of trouble with a homework assignment for a fluid mechanics course. I'd like to ask if my solution method is appropriate. The goal of the assignment is to determine the pressure coefficient distribution along the upper and lower airfoil surfaces and plot it (I'm using MATLAB for...

I've done an experiment lately on the NACA-0012 and I've found that as the angle of attack increases, the moment becomes more negative. I wanted to know what does that negative value say about the characteristics of the airfoil, and what is its importance. If someone could help me out, this...

a thin airfoil at a geometric angle of attack (alpha) in a uniform stream of inviscid incompressible fluid has a parabolic mean camber line described by z(x)=4z[(x/c)-(x/c)^2] where z is the maximum camber. Use thin airfoil theory to calculate the following: 1. Lift coefficient 2. pitching...

A superfluid has zero viscosity. Lift of an airfoil (and any shape for that matter) is zero without fluid viscosity. So, superfluids shouldn't generate lift when flowing around an airfoil. Is that true? I think it is impossible for a superfluid not to generate lift on an airfoil, because...

I working on a new airfoil design. Please tell me the airfoil having highest lift to drag ratio, I need it for comparison.

Does anyone know of any available data on velocity measurements in front of an airfoil. I have written a program to calculate the velocity field in front of an airfoil and I need to validate my results but I am having trouble finding any useful data or theory.

I would like to simulate the flow around a 2D airfoil up to M=0.9. Could you please recommend me some bibliography?

hi, i am a mechanical engineer currently working on the design of a UAV. Our rough sketch kind of resembles Burt Rutan's Long-EZ or Velocity. I am attaching a couple of sketches of the aircraft which my team and i have constructed using XFLR 5. We will also be using XFLR 5 and Profili for...

bernoullis theromen - 1)when a fluid flows through narrower cross section it should move at higher velocity to maintain mass flow rate. 2)for a fluid to move at a higher velocity as in the above statement the pressure difference between the higher cross section and lower cross section...

Induced drag of an airfoil should be inversely proportional to velocity^2 wiki states "Since induced drag is inversely proportional to the square of the airspeed" Ok but [Induced Drag = 0.5 * Density * Velocity2 * Wing Area * Induced Drag Coefficient] which is proportional to the veloicty^2 and...

Hello all, I'm trying to design an efficient airfoil for a wind turbine blade. To be entirely honest, I'm not entirely familiar with this field of engineering; I mainly specialize with steam applications, so this design attempt is obviously a somewhat far cry from that! Yet I've been trying...

I am given a project to transform an airfoil from a cylinder using joukowski transform. The cylinder is in zeta plane and the airfoil is in z plane. I did the plotting and i got the airfoil shape using matlab. but i want to know how to plot the pressure distribution over the airfoil. The...

I am currently preparing for a few wind tunnel tests on a NACA 2412 airfoil. The lab technician told me that before I can use the tunnel, I need to provide solid proof that the models will be able to hold up in the wind tunnel (up to speeds of 110 mph (30 psf)). In the technician's own words...

I am constructing a few model airfoils for some low speed wind tunnel tests. I will be using wooden ribs covered in Mylar. I was just wondering what kind of wood is best for this situation: balsa, basswood, or a different kind of wood. Thank you

When an air passes over the wingtip of the airfoil, the upwash created at the leading edge 'reduces' the Angle of Attack, thus reducing lift. So why does this affect increase induced drag. The way I understand it, the greater the AoA (more lift), the more induced drag that is generated. Help...

Homework Statement I have recorded raw pressures for from a wind tunnel for a NACA 0012 airfoil with 30 surface pressure taps. I have computed Reynolds Number for 3 angles of attack. I have computed the Pressure Coeff. for each pressure and graphed them verses the non-dimensionalized...

Hi, velocity of air=0, an airfoil or wing with is moving forwards with a velocity of 40m/s at an altitude of 1100m. At a certain point close to the wing (which is a point on top of the wing) ,the air speed relative to the wing is 50m/s.Find the pressure at that point. Somebody pls help...

What makes the air, flow much faster on top of the airfoil, when compared with the bottom surface? In engineering terms, why is there a relatively higher rate of change in velocity over the top surface? and is there any mathematical derivation/proof for coanda effect?

Hello Guys, This Is My First Day ,first Topic,first Question In Here And I Would Like Some Body To Help Me As Soon As Possible,i Dont Know If I Am In The Right Place Or Not But Let Me Give It A Try... My Question Is Related To Half-dimond Airfoil,i Would Like To Know How To Calculate The...

hi i m making a miniature aircraft...:frown: :frown: :frown: but i m struck with the problem of many... i have to fly my aircraft at about 20m/s(72km/hr=45 miles/hr) at about an altitude of 15-20m... wing span is 2m(it cannot be more than this acc to the rule of competition(fuselage also not...

Hi guys, I've heard that this topic has been discussed to death before but hopefully not here yet I apologise if it has been. I'm currently in high school we're just into bernoulli's equation and one of the applications is the airfoil. Our textbooks states that the fundamental source of...

hello once again... now i need to find specific information about aircrafts of the ww2 and the airfoils that they used... all of this for subsonic aircrafts... pictures and information for a presentation... thanks once again

OK, I have two labs, one in Calc 3, one in aerodynamics. In calc 3, we are using an airfoil described by a piece-wise function. How can I figure out what the name of that airfoil is? By that, I mean can I match up the airfoil to the function given? Or will I have to work backwards and...

hello people. i´m a aeronautical engineer student and i need to do a work about low speed airfoil.. can anyone tell me where i can get information about this subject.. thanks

Does anyone have a solidworks sketch of this airfoil? I would like to use it for a COSMOS analysis for a lab I am doing. Thanks!

OK guys, I need some help. I need to find a low-speed airfoil, about 30 mi/h. the plane will only be like 12-14 lbs of takeoff weight. just a basic airfoil or a source so i can get the drag.

Hello, we've just watched a few movies about drag, reynold's number, etc., as part of our fluid dynamics course. In one of the movies, they claimed that given a laminar flow around an arifoil, the velocity of the fluid at both ends of the airfoil is zero. Now, I understand why the velocity is...

I'm looking for either tables or graphs which show variations in moment coefficient (either about the 1/4 chord or the leading edge) as angle of attack changes. I have details for a handful of NACA standard airfoils from Anderson's Intro to Flight book, but I'm looking for more. Most of...

I invoke those aero-brains flying around here in order to help me in these questions: I want to simulate numerically using Matlab the potential flow around an airfoil. The first question is if anyone of you knows if is it possible a steady solution of such potential flow (subsonic and...