Drag coefficient Definition and 90 Threads

While writing a physics report, I obtained a data that for balls of rough surfaces, there is a higher drag force and thus the ball can stay stable at a much smaller angle when put up in an airstream. However, while analyzing this result, I found out that the drag coefficient is not always...

I am new to the forums and need help with something. I have been using a spreadsheet that somebody else made in order to help me design an electric motorcycle. I have been inputing my own data using most of his calculations and I have noticed that he did not calculate any aerodynamic parameters...

Homework Statement angled piece of sheet set at various distances to a set fan, the sheet is placed on scales and they measure the amount of force the wind creates. There are noticeable differences at the different distances and angles. Homework Equations wind force and wind pressure...

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.

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 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...

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?

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...

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 ! 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...

Can anyone PLEASE help me in pointing me in the right direction? I need to obtain drag coefficient calues for I-beams. I found a site stating it was 2.7, but it says nothing about the orientation?? I basically need the Cd-value for flow parallel to the I-beam, from the top and from the side...

Hi I am currently trying to work out the drag coefficient of a car, I know the formulae to work out CD, this being CD=FD/0.5xρv^2A. I can not figure out how to find FD as the formulae for this requires CD. Is there another way to find FD? The information I have is as follows: Car Mass: 1350 kg...

Hi I am currently trying to work out the drag coefficient of a car, I know the formulae to work out CD, this being CD=FD/0.5xρv^2A. I can not figure out how to find FD as the formulae for this requires CD. Is there another way to find FD? The information I have is as follows: Car Mass...

Homework Statement A golf ball and a basketball are both moving through the air at 10 m/s. Which has the higher drag coefficient? a. The golf ball's drag coefficient is much higher. b. The basketball's drag coefficient is much higher. c. Both drag coefficients are about the same...

HI i have been involved with a problem which requires me to calculate the drag of a finite circular cylinder of very low aspect ratio (~1.2) i.e the h/d= 1.2 The Red= 5.4x 105 (based on diameter) and the Rex = 8.46x 106 The flow regime is very low subsonic ( M=0.15) I need to predict the...

Calculate velocity of the skydiver of mass M= 80kg as a function of time. The air drag coefficient D= 100g/m = 0.1kg/m. Assume that the skydiver has v=o at t=0. In my book high speed air drag is f=Dv^2. I found Vt= 88.5 m/s with Sqrt(mg/D). BUT this is not the V they are asking for :(...

Approximetly how much is the drag coefficient if orginally the coefficient is 0.02689. I know it depends on aircraft etc but I am only looking a rough estimate.

I have been trying to find lift and drag coefficients in terms of pressure. So far I have found multiple equations. Below is what I have found after multiple research on the web. I am using these equations in LabVIEW. My input is going to be upper and lower surface pressure and I have to find cl...

Hi, just found these forums, and they look very useful. I'm a second year Aerospace Engineering student, and as part of a project I'm modelling the first stage of a Saturn V rocket. I'm using a linear and non-linear model, and have all the equations sorted out. The only problem is I can't...

hi i need to calculate the drag coefficient of a rotor bade(with two blade).infact i need to calculate the torque by drag,then power required for rotate that rotor on a fixed test stand. who knows about what formula or chart, diagrams... thanks in regards sadegh

Homework Statement hile playing pool on a cruise ship, you accidentally hit the cue ball over the railing and it falls into the ocean below. If the cue ball (a sphere of diameter = 57.15 mm, m = 160 g) reaches a terminal velocity of 1.55 m/s in the water (), what is the drag coefficient of...

Homework Statement I need to find an expression for the minimum drag coefficient, C_D, of an aircraft during straight and level flight. Homework Equations C_D=C_{D_0}+kC_L^2 Where: C_{D_0} is the profile drag coefficent C_L is the lift coefficient k is just a constant The Attempt at a...

hi small question in the drag coefficient formula for boats and ships, is the reference area, the surface area of the submerged part of the ship/boat? demson

Homework Statement I made a wind tunnel for a science project and i am trying to determine its windspeed. I decided to suspend a pingpong ball on a string in the wind tunnel and measure the angle change. But to do this i need to calculate the drag force and i cannot do this without knowing the...

Hi In a Drag problem, I'm trying to calculate the drag force but I don't know the drag coefficient? Is there any way to calculate it? Thanks

Drag Coefficient out by a factor of 10, can anyone help?? Im doing an experiment on the drag of a sphere and am trying to work out the drag coefficient. From looking at data online this should be around 0.5 (its a smooth sphere). Using a wind tunnel I measured the drag for various sizes of...

Hey guys, I'm working on a lab here about pressure variation normal to streamlines. For the last experiment, there is airflow around a cylinder with a static pressure tap. The pressure tap records Cp (divides by dynamic pressure) and angle of rotation. I have data points for Cp vs Theta (10°...

So, after looking at all the stuff those geniuses up at NASA came up with, I'm trying to figure out how to get the drag coefficient for the Apollo 13 command module reentry. Heres the stuff I thought were important: Entry-interface 400,000 ft 36,129fps Drogue chutes deploy at...

We are doing a project on the terminal velocity of a badminton shuttlecock and also have to find the drag coefficientof it. The problem that i have is that we are doing this very low budget I.E. throwing the shuttlecock from a window and filming it, now if i am correct to find the Cd we need to...

Is there any experiments I could do to prove that the Drag Coefficient of a Sphere is more or less 0.5 depending on the roughness of the sphere?

I have a general question concerning the affect of surface treatments or imperfections in the painted surface of the vehicle in relationship to the Drag Coefficient for an automobile. I own a 2006 Hyundai Sonata which has a drag coefficient of 0.32. Over the last six months I have noticed a...

Hi Does anyone know the drag coefficient of a missile. Would a missile have a lower drag coefficient then a torpedo? Thanks all

I know the equation for terminal velocity and drag coefficient. But I can't find one without the other. It's a real catch-22. I also don't know the Drag Force. HEEELP!

Hi, I am designing an experiment for an individual project and it happens to involve aerodynamic. I wonder if someone can give me some idea of the drag coefficient of a square piece of flat paper (the normal 80grams photocopying paper) traveling through air against its face? (i.e. not...

Ok, I think I'm getting a hold on this problem, but I want to make sure I'm in the direction... Homework Statement Let \inline{v_\infty} be the terminal velocity of a falling body in air. If the body is dropped from rest, find the expression for the speed as a function of time (1) if the air...

A fire helicopter carries a 560-kg bucket at the end of a cable 20.6 m long as in the figure below. As the helicopter flies to a fire at a constant speed of 39.2 m/s ,the cable makes an angle of 39.6 with respect to the vertical. The bucket presents a cross-sectional area of 3.96m^2 in a plane...

Hello. I'm looking for a drag coefficient of a high molecular PVC material over sea water (fresh or ocean water) I'm designing an electric outboard motor for an inflatable boat I got and was wondering how much ft-lb thrust I would need to go certain speed (~5-10 mph), considering weight (~530...

Drag coefficient formula? What is the formula for finding this out? Sorry, for being n00bish and for this not being posted in the relevant forum but this one has the most people viewing so I thought I'd get the quickest response this way. Thanks. O yea, I've tried searching, but sifting...