Drag Definition and 713 Threads

Hi This isn't a homework question, just a problem I thought up of but would require some implementation I don't really know how to do. Homework Statement If I have a microfluidic channel with laminar flow and a parabolic velocity profile as predicted in the Hagen-Poiseuille flow, and I...

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...

http://www.youtube.com/watch?v=_EU-raX_40Q&feature=relmfu This link demonstrates the modelling of projectile motion with drag. I was just wondering if anyone can help me find the downloadable link he mentions at 5:23

Heyy uh I have this problem I'm confused about; there is a body at rest (a sheet of cardboard set at an angle to electronic scales) and a fan blowing at the surface area. There is noticeable difference when I adjust the speed of the fan, the angle it sits at and the distance to the fan. Anyway I...

Homework Statement Hello guys, I am here and really need your help. In the figure below, the water flow from inlet and then out at outlet with velocity, v = 0.71 m/s. The objective is to calculate find the drag force and lift force act on fishing lure. I have done Ansys Fluent analysis but...

I was wondering, if the force that causes a car to move in one direction is matched by the drag force opposing in the other direction, why does the car move at a constant velocity rather than moving at zero velocity. I thought that when one force opposes the other equally, there is no net...

I am trying to predict the flight of an object with a parabolic trajectory including drag due to air resistance how do I do this? the wiki page was not clear its my understanding its relative to the square of the speed.

Hi All, Assuming Stokes drag, wikipedia suggests this problem (the solution for v(t) ) has an analytical solution. Is this right? http://en.wikipedia.org/wiki/Drag_%28physics%29#Very_low_Reynolds_numbers.E2.80.94Stokes.27_drag Could someone point me to the derivation online? Or a...

Alright, I am trying to work out some equations on a project to determine if fictional instances of physics are possible or not. In my case, I am seeing how a person travels if they are thrown from a jet that is traveling vertically (don't ask). I have completed the equations to solve how far...

The drag force can be affected by the velocity of the object relative to the fluid. Does that mean the wind affects the drag force, since it changes the velocity of air particles?

What wing area should a plane weighing 2000lbs have to enable it to land at a speed of 35mph? Max CL= 1.50 Formula for lift lb= CL*ρ*A*v^2/2 when i set up the problem i get this 2000= 1.50*ρ*A*(35)^2/2 and i realize I am trying to solve for A (area) but what does the ρ...

Homework Statement I've been given the mission to find out the drag coefficient for the Ahmed Body. The drag coefficient itself it too hard to measure. The problem for me is to find a way to separate the drag coefficient to Pressure Drag coefficient and Skin friction coefficient. My question...

Myth Or Fact? -- Wind drag on flaming arrows In a stable atmosphere would arrows that have their head on fire accelerate faster than a regular arrow?

I am running ANSYS fluent simulation flow over naca 0012 airfoil. So far the lift coefficient is similar with the published papers. The problem is drag coefficient is different so much in term of value compared to published papers. I have check my mesh quality and boundary condition, it shows...

http://en.wikipedia.org/wiki/Drag_coefficient from wikipedia, it is written 1.98-2.05 for flat plate perpendicular to flow(2D) , but I have a differrent b/h ratio plate, where h=157mm and b=816mm , b/h=5.197 how to get the drag coefficient in this case? Thanks.

Hi, Can anyone help explaining the points of action of drag and thrust forces on an aeroplane in flight and also the realtionship between Lift-Drag ration and wing configuration?! Any help would be great!

I'm trying to model the flight of a small spherical object (such as a ping-pong ball) through air at smallish velocities (\approx 5{_{m/s}}) with linear drag so that F_{d}=-bv. The problem is, I can't find a table of linear drag coefficients (b) anywhere; it's always just the normal drag...

Hi I know what pressure and friction drag are, I am having a hard time trying to find out how can you calculate the coefficient of drag for them? I think i have came across an equation for it: F_{D} = .5*ρ*v^{2}*A*C_{D} where F_{D} is the force of drag, ρ is density, v is velocity, A is the...

Homework Statement An object moving in a liquid experiences a linear drag force: D =(bv, direction opposite the motion), where b is a constant called the drag coefficient. For a sphere of radius R, the drag constant can be computed as b = 6 pi n R, where n is the viscosity of the liquid...

Hi, An object is falling near the surface of the Earth. We assume there is a drag force acting on it due to the air molecules. It's initial conditions are such that it rotates and is in a chaotic motion. Will the object will fall in the end in such a way to minimize air drag? And if yes -...

The linear drag coefficient is a function only of object size and medium viscosity. Multiply sources say viscosity of air is independent of pressure and density. How can the linear drag be independent of density of the medium? It seems like less dense medium should mean fewer collision and in...

Hi I am a mechanical engineering student currently busy with my final year project on spoilers I need to design manufacture and test a device to test different spoilers it must determine the drag coefficient of the spoiler and the down force generated by the spoiler without the use of an...

The figure shows a graph of actual position-versus-time data for a particular type of drag racer known as a "funny car." Estimate the car's velocity at 2.0s Equation: v = m/s I thought I knew how to solve this, and I made a tangent line at the curve and 2s, and when I do the slope at...

i want the gear so the car is going 100 mph at 6000 rpm 1:1 drive at end of 1/4 mile. have figured out this much for dry run. 32 inch DIAMETER tire x pi 3.14 = circumference. let's call it 100 inches. one mile is 5280 feet. engine will turn at 6000 RPM. RPM is in minutes. MPH is in hours...

Homework Statement Consider a rocket is subject to linear resistive force, f = -bv . \dot m is constant. Use the equation: m \dot{v} = -\dot{m }v + f to determine the velocity of the rocket : since the rate of mass lost is constant let \dot{m} =k vex = nuzzle velocity v = \frac{k}{b}...

How can I design an experiment to find the drag coefficient of a cone without knowing the force of drag that is acting on the cone? Is this even possible?

I am trying to write a java program to simulate the motion of a projectile undergoing a drag proportional to the velocity squared, but i am having some issues writing the acceleration part. This is my attempt, not sure if its right though; a=g-kv^2 da/dt=-k dv^2/dt since dv^2/dt=2vdv/dt...

Simplified drag equation?? Hi, I am a 3D programmer and I am trying to apply drag to some of my objects in my software. After looking around and from previous research i know that calculating drag isn't such a simple thing to do and involves knowing air density, object area and the drag...

Hi guys, I have been trying to measure the drag characteristics of a wind tunnel model by using a pitot-static tube set up. From which the transducer will output to me the stream-wise velocity profile based on the pressure differential measured. Following which, in order to evaluate the...

Homework Statement Find work of drag force in term of proportional to Velocity (Like: Wd=kV^n ,when k=constant value n=Real number) Homework Equations (Fd=1/2*ρ*v^2*Cd*A) The Attempt at a Solution I've a problem with my science project. I try to find the terminal velocity of a...

Homework Statement A blimp of mass 110 kg is pulled at an angle of 52 degrees downwards with respect to the horizontal for D=7 km on level ground at a constant velocity v=14 m/s. If the coefficient of drag (K in F=Kv^2) is 0.5 kg/m, how much work is done by the person pulling? Homework...

Hey guys, I've been looking around online and only find formulae for car passing through a distance with an initial velocity but nothing to calculate the speed of an object starting from a stance and accelerating to complete a distance. I have a car that has done a 1/4 mile (375m) and...

Homework Statement Calculate the pressure drag cofficient for a cylinder using the trapezoidal and simpson's rule (assume the flow is the same on both sides of the cylinder). Angle (deg) Cp 0 1 30 0.274 60 -1.565 90...

If you have a falling object and wind in the horizontal direction, the object ends up falling to the ground at an angle. Why does the drag force only have a vertical component? Thanks!

Hello, everyone! Any ideas how to measure drag or drag coefficient on a body of simple shape? We should conduct an experiment without use of sophisticated equipment. Thank you!

Hi everyone, I am hoping that someone may be able to advise me on an issue i currently have. I am trying to implement a Physics computer simulation (only basic) designed for children learning about forces. One of the sub games that i have created is to fire a character from a cannon and find...

Hi ! First at all thanks for read, I'm new in the forum ... So the problem is, I would calculate the drag coeff of a car but in the coeff formula I would like to know which AREA is considered for this. drag coeff is given by = 2F / ρ(V^2) A Where : F is the drag force ρ is the mass...

I am doing a project where in a pedestal fan is alternatively powered using a flywheel. The flywheel is brought to some initial angular velocity by the electric motor. Now, if the power goes off, the fan blades would be coupled to the flywheel and it continues to rotate for the next 10 minutes...

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...

Was having a breakroom discussion today and I figured I would get an outside opinion. Anywas I have to projectiles/particles flying through the air and are unaffected by gravity. Both have the same drg coefficient, cross-sectional area, air densityetc. The only differences are particle A has...

Hey all, I have been mulling this around in my head for awhile and cannot make sense logically. In thinking about a sphere falling through some random liquid, how does decreasing the diameter of the sphere affect the rate at which it falls? I am thinking of two formulas and the seem to...

Homework Statement a ball makes a free-fall with zero initial velocity and an arrow with 25 m/s initial velocity is thrown to shoot this ball at the same time. The ball is initially h=38 m higher than the arrow. a) Assume no drag force then how long after does this collision occur? At...

For the motion of a spherical ball under water, can its drag force be calculated by knowing only its mass and deceleration?

Homework Statement So the question I've been asked is, that there is a moving car, at time t = 0, moving with a speed of 50 km/h. At t = 0, the car stops accelerating, and thereby slowing down due to two forces: The air resistance drag force A friction which is created by some magnets...

Homework Statement A particle of mass "m" whose motion start with downard velocity V0 in a constant gravitational field. The drag force is quadratic and proportional to kmv2. What is the distance s through which the particle falls in accelerating from v0 to v1. Give your expression for s in...

A) You drag a suitcase of mass 10 kg with a force of F at an angle 48 with respect to the horizontal along a surface with kinetic coefficient of friction 0.32. The acceleration of gravity is 9.8 m/s2 . If the suitcase is moving with constant velocity 2.25 m/s, what is F? Answer in units...

I maintain a small piece of software for the Airsoft/Paintball community. I include some basic energy and velocity calculations but I have also as of a few versions back started including more "theoretical" calculations like how far a BB will travel and that sort of thing. I want to improve the...

Basically, BB ammos were shot from an airsoft gun into a water filled tank. The experiment was recorded using a video camera. I can calculate the approximate instantaneous velocity of the bullet under water at a given time using Logger Pro. 1. Relevant equations Drag force = 0.5 ρAC0v2 2...

Homework Statement A projectile of mass 1300kg is launched from the ground (x =0, y =0) initial velocity components Vx=Vy=108m/s aerodynamic drag force is of magnitude C(V)^2 where C = 0.6 Homework Equations Finding the range and angular momentum initial and final The Attempt...

Would anyone know how to determine the area that a drag shield would have to be to allow an object above not to experience no more then .001 Gs? The drag shield that I was thinking about is just a flat sheet attached to the bottom of the top object by a string. Would this even be possible?