Questions tagged [aerodynamics]
The aerodynamics tag has no usage guidance.
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Honda NR 500 Windscreen
I'm looking for the story of this extremely unusual bike. I found very interesting the experimentation done.
When talking about this bike, most people think about oval piston, but my question is about ...
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Multiple inline fans
I have a chimney with a single 100 cfm exhaust fan. If I would add a second similar fan in the same chimney,in line with the first fan, what would happen? Would I move 200 cfm? Would I still move 100 ...
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How to theoretically determine the flow rate for a fan design?
I am trying to design a ducted axial fan. The fan will be pulling air through a filter, and ejecting out into the atmosphere (For a CO2 direct air capture application). However I want to start with ...
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Density or Pressure based solver CFD
I’m currently trying to simulate the 2d cross section of a bullet using Ansys Fluent but am really confused about which solver type to use- density or pressure based?
Conditions:
Transonic (M=0.8)
...
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What are the limits on plane speed?
I was thinking about an extremely narrow object and considering that I think in the ideal case it could only deal with the force of collision with air particles at the front of the projectile (...
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Pitot and static port placement - How to choose the ideal location
Forgive the this topic placement as it might be similar to other older ones (Although I a bit sure that the main contents might be different than other older ones).
In the upcoming days I will have a ...
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How Does The Aerodynamics Of This Hanging Rotating Wing VAWT Turbine Function?
We are examining videos of this very fast rotating "hanging VAWT" shown on Youtube:
https://youtu.be/O2MZsK0mvBk
https://youtu.be/7hVQ_rVNRUI
It say in the text description that "...
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how to calculate drag force (to be used later in the calculation of drag coefficient)
I'm working on a school project for car design (M segment car) we already found an open source Toyota model and can get the final answer online, but I want to know how can I calculate them
what's on ...
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What is the approximate horsepower/kW output of a cyclist riding a bike at near ~300km/h?
In 2018, a female cyclist set the outdoors record for fastest cycling clocking in at almost 300km/h. (https://en.m.wikipedia.org/wiki/Denise_Mueller-Korenek), and I am curious to know the approximate ...
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How to calculate missile's radius of turn?
I want to make a simple simulator game and in this game there is a missile that must hit something.
The problem is, I can't find the equation to calculate its radius of turn.
The game is a simulator ...
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Scroll design for off the shelf tangential/cross flow fan rotor
I'm trying to figure out a somewhat optimized fan scroll shape for a cross flow fan rotor I aquired. However I seem to have vastly underestimated the complexity as I have a lot of trouble finding ...
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How to calculate the increase in air speed from a wind nozzle / concentrator?
Given an inlet wind speed of $v_1$ and nozzle inlet area of $A_1$ and an outlet area $A_2$ what would be the outlet velocity. The nozzle/concentrator is positioned in an open field where the wind is ...
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Wind drag by a solar panel on an RV trailer
I installed my solar panel a couple weeks ago and now I'm not sure if I did it right. The first pic is mine the second is the other guy. it’s what brought up the curiosity, as this guy has the same ...
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How air dam reduce drag and lift?
Few questions about air dam(flexibile vertical plate on front bumper)
What is main purpose of air dam in car industry, reduce drag or reduce lift(increase downforce)?
How dam reduce drag if : a)...
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Converting differential pressure
I need to submit a lab report.
I've measured:
Differential pressure [Volts]
Flow rate [Hz]
Flow Rate [m^3/s]
In my report I need to get the Pressure Differential in Pascal but how can I convert ...
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Does the weight of a pilot exponentially affect the necessary weight of human-powered aircraft?
The MIT Daedalus, a human-powered craft, weighed about 31 kg. This was significantly lighter than its pilot during its record setting trip, though I can't confirm the pilot's exact weight. Still, this ...
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Releasing compressed air with the loudest pop
Due to the dry summer I've been thinking about theory of making cracker/banger without fire. Would connecting a nozzle (de Laval?) to quick release valve from small cylinder with the pressurised air ...
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Stochastic parametric stability of structures
I am investigating an engineering problem that relates to the dynamic stability of a beam-like structure under the action of a stochastic excitation (say, e.g., a marine structure acted by waves or a ...
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How do water tunnel experiments compare to wind tunnel experiments?
I recently stumbled across the water tunnel videos by this guy:
https://youtu.be/quDLzxmJl5I?t=838
He states that for his "high flow" experiments the water speed is at 0.668 m/s. The car ...
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Governors and acceleration effect on IC engine
If a car is moving with a constant velocity this means that resistive loads (like air drag friction) should equal the driving force from the car; but I know that the governors always cancel the effect ...
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Propeller design software & Javaprop help
I'm looking to recreate a 21 inch diameter RC plane propeller for cruising at 30m/s. I have been using javaprop but after inputting the information such as thrust, rpm and hub diameter the blade ...
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Angle of attack on variable pitch propeller?
For a variable pitch propeller where the angle of attack can be adjusted during flight, are the individual blades similar in design to standard propellers, with a low angle of attack at the edge of ...
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Why do air-to-air missiles have tail fins?
That sounds like a stupid question but hear me out.
For something like a rocket where the goal is to fly in a straight line the use of the tail fins is obvious. But air-to-air missiles are designed to ...
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What aerodynamic equation should be used to determine the drop in air pressure over an airfoil embedded within a vertical pipe?
I have a conceptual idea for a thruster for a VTOL aircraft/drone which should produce lift by utilizing a upward-flowing airflow to produce low air pressure over the top surface of an airfoil that is ...
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is there a difference in performance between these two fan designs
These two fans are usually used in hairdryer is there a difference between them in performance if both have same rpm and same outer diameter.
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Where is best place to install vortex generators if race car diffuser stall?
If flow separate in high AoA diffuser, vortex generators can help to delay separation.
Where is best palce to install VG for flat floor + diffuser configuration , in front leading edge of diffuser or ...
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What are the advantages of an asymmetrical missile nose cone?
Some rocket- and missile designs sport an asymmetrically conical nose cone. A prime example being the Stunner missile in "David's Sling" surface-to-air system.
Several sources (such as ...
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What are the practical applications of Centre of Mass & Centre of Gravity?
I have learnt COM and COG are different things if we have non uniform gravitational field i.e. mass will be same at anywhere but gravity will be different. I want to find practical examples of both ...
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Why wind turbine dont use high lift coefficient airfoils?
All wind turibne use low lift coefficent airfoils from 1.0 to 1.5.
Why not use high CL airfoils to get maximum torque?
http://airfoiltools.com/airfoil/details?airfoil=s812-nr
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Is the main goal for wind turbines to take maximum energy for a given diameter?
If you increase the number of blades, that will increase torque, for the same RPM you get more power,...simple logic
So why only three blades, is main goal for wind turbine take maximum energy for ...
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Kelvin's Circulation theorem applied to a cup of tea
Recently, I dipped my spoon into my tea. I saw that as I dipped my spoon into my tea, two vortices formed at both edges of the spoon. I guess this is similar to vortices forming at the end of ...
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Is the drag coefficient/velocity of of a vehicle based on frontal area?
Does the frontal area of a vehicle determine the velocity/drag coefficient of a car?
A Ferrari 458 has a Cd of 0.33 while a Corvette C6 has a Cd of 0.29. Does this mean the Corvette will have less ...
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Convert from mm of water to Coefficient of pressure (Cp) [closed]
Okay,
I have this value in mmH2O (2.650) and am not sure where to go next to convert it to aerodynamic parameter pressure coefficient please?
mmH2O * 9.8066 = N/m2
???? What do do next please?
I ...
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How can a car travelling at a higher speed may cause it to lift off from the ground?
Many Sports cars and other high speed and performance ground vehicles have a rear wing attached to its rear, and a splitter attached to its front. From what I understand, the rear wing (which takes ...
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Vortex diameter
There exists clear definitions of the size of a vortex core, but vortices affects it surroundings beyond this core. An example is a wing tip vortex which has a small core, but can be seen as a big ...
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How to determine the stability of an aerodynamic shape in ANSYS Fluent
I have the aerodynamic outer mold line file of a drone. The first task of the school project is to verify that the drone is stable. First, I used the 2021R2 version of ANSYS Fluent to try to find the ...
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Why flow around an airplane is different in different frames of reference
In the book Fluid Mechanics by Yunus Cengel it was written
"Flow around an airplane, for example, is always unsteady with
respect to the ground, but it is steady with respect to a frame of ...
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Are there any methods to figure out how aerodynamic a race car is without a Cd number?
For the top speed of a car, I believe it's usually limited by drag and horsepower. However, I've also learned that gearing can affect the top speed and acceleration of a car. Are there any methods to ...
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Does more downforce affect the acceleration and top speed?
How can downforce make a race car faster, apart from being faster around corners? I just recently learned that downforce can help a car accelerate from 0-60 mph faster. Usually, I thought drag didn't ...
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What affects a car's overall top speed?
I've always wanted to know how a car's top speed could be determined. Usually, I thought it was horsepower and aerodynamic drag. I learned that weight can affect top speed, but I've recently found out ...
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How can a piece of paper be shaped to guarantee it falls slower than a plain sheet of paper?
My son and I are playing "MAKE" (think "HORSE") and we challenged ourselves to build the slowest falling object using only a sheet of paper. We cannot build anything that falls ...
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How long does it take and how far does it travel a sphere in free fall before reaching a percentage of the terminal velocity?
Assume a sphere (hail) that is free dropping in air. At some the sphere will reach close to the terminal velocity. The question is:
how long $t_p$ in seconds does it take before a percentage $p$ of ...
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Does the terminal velocity of a sphere in free drop increase with increasing diameter?
I was trying today to calculate the terminal velocity of a hailstones with increasing diameter and mass. I was trying to figure out if larger hailstones will have a higher impact velocity or lower.
I ...
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What is the velocity of a fluid particle at the center of a infinitely long counter-rotating vortex pair?
Let's take circulation strength of each vortex τ and distance between them is r.
I feel the answer should be 2τ/πr but my friend is arguing its τ/2πr.
So my thought process goes like, if you have a ...
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Will a lift force be created by the Coanda effect if high velocity air flows under a half-toroid shaped saucer? [duplicate]
I would like to know if a lift force will be created by the Coanda effect from high velocity air that is directed under a half-toroid shaped saucer by a centrifugal impeller.
To illustrate how such a ...
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What is the side way force on a flat membrane place perpendicular to the flow of current on one side, and stagnant water on the other
So basically imagine a plate being placed parallel to the direction of flow of water with water flowing with a certain velocity on one side of the plate and on the other side it is almost stagnant. ...
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How to properly use the lift-curve slope for divergence calculations?
I was reading Wright and Cooper's writings on static aeroelasticity and I think I'm missing something.
To calculate the acting lift, the equation $L = q S a_1 \theta_0$ is used, where $q$ is the ...
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Which of these propeller configurations is most efficient?
All propellers shown in the figure above are identical and are operated at identical speeds with four separate (numbered 1 through 4 vertically) configurations illustrated. The physical distance ...
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Why don't we use feather like structures for hang gliding?
I'm not entirely sure if this is the right site for this question, but I recently went on a Greek Myth Binge and came across Daedalus again, and his famous first hanglider, made from feathers. Now, ...
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Is it known how streamlined the Shinkansen 800 bullet train is when on rails?
This question is different from What is the optimal streamlined shape?. That question is probably about an ideal situation of flowing through space with no gravity in a fluid with zero viscosity and ...
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