Questions tagged [aerodynamics]

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1answer
139 views

I have a problem with my representation of roll in Simulink

I am currently an engineering student and a member of the aerospace club of my engineering school (ESILV) which is called LéoFly. We’re a team of 12 students and are building a Fusex (...
3
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0answers
42 views

Mathematical transformation of a heading angle to a roll angle

I'm trying to understand a function in a SIMULINK example of a path following UAV simulation. The gist is that, the UAV Waypoint Follower block provides a required heading from a list of waypoints and ...
2
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0answers
28 views

Convergence problem in RANS simulation of unsteady flow

I am simulating an air flow through a two dimensional rectangular channel. The channel splits into two channels, one of them is followed by a 90 degree bend downwards and leads into a cylindrical ...
2
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0answers
34 views

How does NASA's QueSST X-59 jet work?

The QueSST (Quiet Supersonic Transport) is a project to create a more diffuse sonic boom in order to use supersonic flight commercially without the usual abrupt 1~2 psf pressure spike damaging the ...
2
votes
1answer
162 views

Calculating mass flow rate of a scramjet engine?

First post here. I'm an undergraduate ME interested in fluid mechanics. I came across scramjets and I was interested about the engine. I want to calculate the mass flow rate of the engine and I made ...
2
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1answer
79 views

In horizontal axis wind turbines, why does axial component of absolute velocity stay constant (wake rotation theory)

I am having hard time understanding how does the axial component stay constant through the rotor. Every resource i look just says it is due to mass conservation but never gives the actual conservation ...
2
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0answers
463 views

Formula for “ram rise” that works all the way to orbit

True Airspeed (TAS) is the vehicle speed relative to the surrounding air. My assumption is that if I am in orbit say at 120 km altitude with an instantaneous velocity of 8 km/s my TAS would be fairly ...
2
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0answers
50 views

A Question of Coaxial Rotors and Lift

I'm only a HS physics student, so please bear with my lack of jargon. My question goes like this: In the scenario of two coaxial rotors spinning independently in two different directions, each with ...
2
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0answers
36 views

what is the actual meaning, role and aim of $p_0$, $V_{a_0}$ and $V_c$ for Mach-meter?

Roskam, book "Airplane Aerodynamichs and Performance" at subparagraph: "2.5.2 HIGH-SPEED AIRSPEED INDICATORS (COMPRESSIBLE FLOW)" uses the following three equations: a) $\left(\frac{\gamma}{\gamma-1}\...
1
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1answer
17 views

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. ...
1
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0answers
28 views

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 ...
1
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0answers
43 views

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 ...
1
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2answers
34 views

Is air density calculated using Total Pressure (Dynamic and Ambient) or just Ambient?

I have some wind tunnel data and static and dynamic pressure are logged (temperature too). I need to calculate lift and drag but I’ve been confused whether to use only ambient pressure to calculate ...
1
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0answers
33 views

Superimposing a Vector Field onto a Toroid in Matlab

I am a systems and control PhD student in Aerospace Engineering. Currently, I am trying to create a wind shear model of a toroidal thermal "bubble" in Matlab similar to the one in this paper (shown ...
1
vote
1answer
34 views

Normal Shockwaves occurrence at cone tip with Angle Theta

I have a question regarding shockwaves. So as far as my knowledge, a flow moving at Ma= 1 will create a normal shockwave ($arcsin(1/Ma)$) , and a flow moving faster will cause an oblique shockwave. So ...
1
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0answers
13 views

Skelet Theorie, can anyone help?

I am studying Gas dynamics and came across the lift angle approximation as based on Skelett Theorie (in german). I have done google searches on finding this theory but no luck on any information. Can ...
1
vote
1answer
44 views

Torque induced regular precession/ nutation calculation and visualization out of attitude Data

I have a rocket body with given Euler Angles, Quaternions and Angular-Velocities for given time steps. And I'd like to calculate the regular precession and nutation for every time step, so that I can ...
1
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0answers
25 views

How to evaluate the fuel consumption rate of an air conditioner in a vehicle?

Using two cases studies: I. When the windows are wound up and air conditioner is turned on. II. When the windows are wound down and air conditioner is turned off. Case studies are evaluated for ...
1
vote
2answers
89 views

Fan starts making noise and air flow is reduced considerably

Yeah.. I dont know if this belongs here, I coulnd´t find a proper stack exhange site for this but it sort of involves physics I guess so... yeah. Basically, I have a ventilator, that after a few mins ...
1
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0answers
41 views

What is the theoretical relationship between sound and mass with respect to the sound barrier as a max velocity?

First post here, forgive me any faux-pas. In regards to compressible flow and accelerating a mass flow, such as in a converging nozzle, I know that you can't accelerate a mass past the speed of sound (...
1
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0answers
32 views

Determination of a Joukowski airfoil chord (demonstration)

I'm currently studying Aerodynamics, and one thing that I noticed is that the maximum and minimum $x$ coordinate of the airfoils (which are necessary to compute the chord) on the transformed plane (...
0
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0answers
15 views

Wind behavior and pattern

From the 5 options, which one shows the worse wind effect? Is it (b) because wind speeds accelerate through a gap? But how about in comparison to (c)? Or (d) due to the height and sharp corners? If it'...
0
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0answers
33 views

Why does the tapered part of a Wing have such high coefficient of Lift?

If we take a Trapezoid wing shape as an example and see that it has low $c_l$ near the root of the wing and very high $c_l$ at the tip. The Lift generated, however, is reversed to the that of the $c_l$...
0
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1answer
49 views

How to do Blade Element Momentum Theory Analysis for NACA airfoils?

I wanna perform BEMT analysis on blades of different geometry and not just symmetric thin airfoil. How to do this?
0
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3answers
463 views

How do drag and downforce in a rear spoiler of a car vary with angle of attack?

I ran an two aerodynamic simulations, one for a spoiler angle of 0 deg and the other for the same spoiler declined at 30 deg. The results showed a considerable increase in downforce, but only a slight ...
0
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0answers
51 views

Determining thrust equations for a custom UAV

I have been tasked to mathematically model and simulate a 2 propeller, 2 motor UAV. But I am struggling with determining the thrust equations, of the propeller, for my design. I know that: Ft = Ct * ...
0
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2answers
102 views

How to determine the banking angle of a quadcopter/helicopter due to unbalanced load along the X-axis?

What theories/equations can be used to determine the banking angle of a quadcopter/helicopter due to unbalanced load, given that the load will only shift along the X-axis
-1
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1answer
29 views

Efficiency of propeller with Wind perpendicular to rotation axis

What happens to air flow and propeller efficiency if it is moving with Wind perpendicular to rotation axis. The air is blowing in a direction lying on the Planet of the tips.
-1
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1answer
23 views

What determines if a shockwave is normal or oblique

So I am studying Gas dynamics and I know the math regarding Normal and Oblique shockwaves, but I am not sure why would one occur and not the other. Is there a rule when normal shocks will occur or ...
-1
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1answer
34 views

Achieving dynamic similitude by sacrificing geometric similitude?

The goal is to scale up a general aviation aircraft by 15%. Dynamic similitude is the primary goal. I have reviewed research on scaling aircraft models but it seems most of it is focused on creating ...
-1
votes
1answer
31 views

What is the most efficient way to heat air?

I'm currently playing with a school project. My goal here is to heat a stream of air to a significant temperature so I can demonstrate air expansion. I have a cylinder, with a few turbines, turning in ...