Questions tagged [aerospace-engineering]

Aerospace engineering is the primary branch of engineering concerned with the research, design, development, construction, and testing of aircraft and spacecraft.

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2
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1answer
91 views

Whats the difference between leading edge and slat?

According to this figure whats the difference between leading edge flap and slat and why the slat come with plain wing and TE flap come alone? thanks.
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1answer
128 views

How can I limit a simulated aircraft's angle of attack?

I am making an aircraft in a simulator (using JSBSIM). Note that I am not a professional. The manual states that it is limited below certain calibrated airspeed to a certain positive angle of attack. ...
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3answers
87 views

What engineering research field is concerned with the mechanics of adhesion; more specifically, how objects behave in soil media such as sand?

I am interested in conducting a research project involving the design of a tool to aid astronauts to perform experiments on lunar surfaces, but I am having difficulties coming up with appropriate key ...
2
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1answer
7k views

How to determine the choke point in a compressed gas system?

I have a pressure regulator bringing an inlet pressure of 150 bar down to 10 bar which is then lead into a plenum followed by a nozzle of area 340 mm^2, exposed to atmospheric conditions. Weirdly ...
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2answers
107 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
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1answer
842 views

Simple, open source aerodynamics simulation software that can import Blender or Sketchup models? [closed]

What are some basic, open source aerodynamics or CFD simulation software that can import Blender or Sketchup models? I am looking for software that is easy-to-use, free, and suitable for educational ...
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3answers
973 views

Apollo 11 gimbal lock flip

I've been studying gimbal lock and am puzzled by something in regards to the Apollo 11 mission mentioned on Wikipedia. They preferred an alternate solution using an indicator that would be triggered ...
3
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1answer
117 views

What does high coefficient of moment mean for an aircraft?

After designing an aircraft idea I had in XFLR5, I noticed that it had a really high coefficient of moment (Cm) compared to other wings of similar size. What does this mean? I played around with my ...
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2answers
269 views

How can I mould a foam-core'ed carbon fibre shape?

I am trying to figure out the best way to mould/ create a closed shape (It is a 500mm long quadcopter arm) that has a foam core, and a rigid good quality carbon fibre outer. Oh and to add to the fun, ...
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2answers
3k views

Can Compressed air be used as a thrust component in a spacecraft to propel the craft through space or to orient the craft? [closed]

Hello I was watching a video recently about aircraft carriers and how they use compressed air to propel aircraft off the ship. It go me thinking if I had, maybe a 50cm x 50 cm x 50 cm spacecraft that ...
2
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1answer
212 views

Smallest possible rocket to get to LEO? [closed]

I was wondering what is the smallest possible rocket to get to LEO. I know that rocket fuel accounts for 90% the total mass of the rocket. Lets say I have 500g of payload and my rocket is made from an ...
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1answer
82 views

What is the smallest eccentricity achieved by an artificial satellite?

As you may know, as eccentricity gets smaller, the location of apoapsis/periapsis becomes less well-defined. Rather equivalently, I've noticed that if eccentricity is < 4e-7 when converting from ...
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1answer
1k views

Chamber Wall Thickness for Liquid Fuel Rocket

In, How to Design, Build, and Test Small Liquid-Fuel Rocket Engines, by Krzycki, page 18 has the following equation: $$t_w = \dfrac{PD}{16000}$$ Assuming the following: Pressure ($P$) in combustion ...
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1answer
798 views

How do I cut a crack into a polymer/plastic?

We need to cut a very thin crack into a polymer plate for a research project. The closest thing to what we are looking for is Wire EDM but since the polymer we are using is not conductive we cant use ...
0
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2answers
426 views

How can we prove that Thrust-to-weight ratio depends by max speed?

Raymer (see source below) affirms "Thrust-to-weight ratio is closely related to maximum speed". Why? How can we demonstrate it? Source: Daniel P. Raymer Daniel P. Raymer "Aircraft Design: A ...
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0answers
220 views

In Raymer diagram “Take off parameter- Take off distance”, what is the difference among “balanced field length”, “over 50 ft”, “ground roll”?

Raymer in his book Suggests a method to find Wing Loading W/S (for example we consider jet with 2 engines) (starting from specific thrust T/W, CLto, density/reference density etc.). In step 1: he ...
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3answers
401 views

Questions about the level flight lift equation

In level unaccelerated flight we have relation $$ W=L=\frac{1}{2}\rho\cdot V_{stall}^2\cdot S\cdot C_{l,max} $$ taken from book Daniel P Raymer "Aircraft Design: A Conceptual Approach" equation (5.5) ...
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0answers
340 views

Determining damped frequency and damping ratio from time domain data

I have some time domain data which are responses of an aircraft to various inputs (example: time vs. bank angle for lateral stick pulse input). I need to compute the effective damping ratio and damped ...
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1answer
2k views

MIMO (multi input - multi output) system decoupling method

A MIMO system with 2 input and 2 output decoupling method to a SISO system is described in many articles and books. How about m*n size transfer functions systems? How can we generalize the method for ...
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0answers
59 views

Sliding mode surface derivative exact matrix format (ds/dx)

Is there any suggestion on sliding surface state derivative matrix (ds/dx) format? ...
4
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1answer
117 views

Sliding mode surface derivative using numerical method

In the article Controller Design using Bifurcation Map for Aircraft Spin Recovery, the sliding surface derivative is obtained using a numerical method. The steady space system is defined by the ...
4
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1answer
88 views

Does a rotating platform on a space vehicle affect the vehicle's trajectory?

Recently I watched The Martian and the space vehicle Hermes in the movie had a rotating platform. I wonder if that would significantly cause the vehicle to be inclined in direction? Does a spinning ...
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1answer
2k views

What is the equation to calculate the Thrust coefficient within a set of parameters?

In the book, Design of Liquid-Propellant Rocket Engines, there is a practice problem written as such. "Determine the design values of $(C_*), (C_f), and (I_s)_t$ for the engine thrust chambers of ...
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1answer
59 views

Illuminate the Earth with an artificial satellite?

Do we have the technology to illuminate a small region on the dark side of the Earth with an artificial satellite in orbit around the Earth? By illuminate I mean bright enough to light objects for ...
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1answer
2k views

How hot does a rocket nose cone get during launch?

More specifically, I'd like to know if unmanned rockets need to be specially designed to withstand the heat generated from air friction and shock waves during launch. I found the diagram below on the ...
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0answers
282 views

UAV 5-Channel Multispectral camera vs. modified RGB camera that resolves NIR

Looking into purchasing a drone. One has a dedicated 5-channel multispectral camera (Micasense RedEdge) the other has a modified Sony RGB camera that resolves the NIR spectrum. Can someone sum up the ...
5
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1answer
471 views

What is "Bernoulli-Lift", and why does it only account for 20% of an airplane's lift?

Whenever the question "Why do airplanes fly?" is asked (e.g. »What really allows airplanes to fly?«, »How an airfoil works?«) at a certain point the following is cited: Bernoulli's principle ...
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1answer
152 views

How do flaps work? [closed]

I understand flaps increase the angle of attack so it increases lift, but how does it increase drag also? Do the lift and drag have a direct relationship?
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2answers
1k views

What is the difference between aeronautical and aerospace engineering?

Every time I search for "aeronautical engineering" on Google I see a few results about aerospace engineering. So they must be similar, but what is different about these careers?
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1answer
221 views

How to calculate propulsive force of gas ejection

How can I calculate the propulsive force produced by ejection of a gas? I suppose it depends on the gas, the velocity with which it ejects, the amount of gas, and some other parameters, like the ...
5
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1answer
668 views

Coupling in a twin engine, tandem rotor power train

Consider a transmission for a tandem rotor helicopter with two engines and two main rotors such as the one below. Both engines are connected with sprag (one-way) clutches such that an engine's speed ...
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1answer
406 views

Calculating amount of propeller pitch for plane [closed]

Me and a team are designing a plane and one of the goals is to have a variable pitch prop, however, I'm a bit lost as to how to do that. A lot of the factors depend on power output of the engine and ...
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5answers
5k views

How is lift related to airspeed?

Lift produced by an airplane wing is related to airspeed - this much is clear; a plane moving too slowly will stall. But what is that relation? Linear? Quadratic? Exponential? I don't need the exact ...
6
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1answer
419 views

Convergent-Divergent Nozzle Design from Exhaust Velocity

I'm working on designing a Cold Spray system that uses a convergent-divergent nozzle to achieve a 800 m/s exhaust velocity. I'm assuming 400 psi nitrogen at room temperature is provided at the inlet ...
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2answers
2k views

Efficiency in a gas turbine or aircraft engine

Most modern aircraft engines, such as the one depicted below taken from Wikipedia, are composed of several compressor stages which are driven by a turbine (or several), and a combustion chamber in-...
5
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1answer
169 views

Calculating real or more accurate specific impulse

This may fall a little under chemistry processes but I felt it has enough pertaining to aerospace to put it here. Basically, I'm in the process of attempting to develop a way to derive $I_{sp}$ as ...
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2answers
1k views

What are the advantages of chemical oxygen generation over compressed tank storage?

Chemical oxygen generation (COG) is used in commercial airliners to supply emergency oxygen to passengers and crew if the plane is depressurized. Weight for weight it produces far more oxygen than ...
5
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1answer
2k views

Logic behind location of shear centre

When we apply a vertical shear force Sy and the structure is symmetric about x axis, then why is it logical to have the position of shear center at the location of intersection of line of action of ...
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5answers
958 views

Can vacuum balloon become possible with this idea?

As it is well known, a vacuum balloon using the materials we have at our disposal is not possible, because of the sheer force they have to resist from the air outside. I asked this question on ...
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4answers
2k views

Aircraft force in g's experienced by pilot

Given: The acceleration of high-speed aircraft is sometimes expressed in g’s (in multiples of the standard acceleration of gravity). Determine the upward force, in $N$, that a $70\cdot kg$ man would ...
2
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1answer
1k views

Which part of an aircraft can most benefit from a structural health monitoring (SHM) system?

In order to reduce operational cost and improve the safety and reliability of aircraft's the aerospace industry and government is increasingly evaluating new ideas such structural heath monitoring ...
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4answers
791 views

Is interference between aircraft an issue for fly-by-wireless technology?

I was reading up on fly-by-wire development, and I saw a short section about fly-by-wireless technology. It seems like a great idea, with the potential to lower costs, weight and complexity. I can see ...
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4answers
747 views

Do all supersonic airliners have a high angle of attack when landing?

The Concorde had a famously high angle of attack (and pitch angle) when landing. This led to its famous droop nose: The Concorde's Russia counterpart, the Tupolev Tu-144, had the same issue. These ...
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2answers
1k views

Would a "lifting body" design be useful for a train car?

Lifting Body The idea of a lifting body design is to shape a vehicle's body in such a way as to produce lift without wings. Research has shown that this can be an efficient method of reducing drag ...
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2answers
197 views

Could adding extra engines to AMELIA disrupt airflow from the other engines?

AMELIA is the product of a partnership between NASA and the California Polytechnic State University. One of its innovations is circulation control. An engine is mounted over each wing, and high ...
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1answer
155 views

Which material is most efficient for the skin of a solar balloon?

Quoting from the Wikipedia article: A solar balloon is a balloon that gains buoyancy when the air inside is heated by the sun's radiation, usually with the help of black or dark balloon material. ...
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1answer
116 views

Do regulations in the United States limit the size of aerial wind turbines?

What with all the work done by the FAA recently on regulating drone usage, I thought it would be nice to turn my eyes to the sky for another, less-known type of aerial denizen: the aerial wind turbine....
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2answers
847 views

How are wind tunnel models used when designing supersonic aircraft?

There are two things involved: wave drag and boundary layer separation. The wave drag depends on the Mach number while the latter depends on the Reynolds number of the flow. It's easy to maintain the ...
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3answers
863 views

Can superhydrophobic surfaces be used to reduce drag?

I am mainly interested in reducing drag in aircraft and I have an idea that I want to learn more about... Can a superhydrophobic coating reduce drag in water-craft such as boats and submarines? If ...
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3answers
1k views

Could air-launched space planes reach escape velocities?

Rockets like the Ariane 5 weigh hundreds of tons, but with about 85% of that weight being fuel, the payload fraction is only about 3% (~10-20 tons). Virgin Galactic is building suborbital space ...