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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Actually real Iron man suit [on hold]

What other people have done: Many people have had this idea. For example Adam Savage's newest video "How Adam Savage built a real Iron Man suit that flies" They used a laser beam to melt the liquid ...
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2answers
48 views

Amount of thrust needed to Hover on the moon?

I am interested in knowing how many newton's of force is needed to keep 1 kg of mass hovering above the moon's surface. And whether the current most powerful ion thrusters would be up to the task? I ...
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Simple but cant find definitive. Effect of diameter/width/thickness on rigidity and torsional/transverse loading

First off, thank you. I love building things and I've recently gotten "interested" in multirotors. I'm really good at gung-ho and I'm in school for mech engineering. So obviously I've decided to build ...
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1answer
77 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 (...
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3answers
121 views

Should Engineers Understand Equations without Relying on Derivations?

As I've progress through my undergraduate engineering program, I've noticed a shift away from physical intuition - understanding why certain phenomena or equations make sense because of basic patterns ...
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1answer
57 views

Pneumatic-based, paddle wheel-type lifting apparatus for aircrafts

I am wondering if a pneumatic-based, paddle wheel-type lifting apparatus would have any practical application within the aeronautical or aerospace fields. Please reference the conceptual drawing ...
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41 views

Designing a PID Controller for Satellite Control

As an Aerospace Engineering Student, I have been trying to make a project of a PID Controller to control the attitude response of a satellite using the parameters from a project called Kufasat. The ...
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1answer
28 views

Is there an easier way to calculate rocket engine Isp?

I am trying to calculate the $I_{sp}$ of a rocket with a thrust of 500 kN. I know that you can calculate $I_{sp}$ with $I_{sp} = \dfrac{v_e}{g_0}$. However, to calculate $v_e$, you need the $I_{...
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42 views

Control law for nadir pointing spacecraft

Hoping someone here can give me some advice. I've been trying to build an orbit and attitude propagator inside MatLAB and have run into some issues with the attitude propagation due to my lack of ...
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0answers
13 views

Feasability of melting through ice crust with radiocative heater

I'm pretty interested in space exploration. Here I'm interested in a moon of Jupiter (Encealadus) which is covered by a thick ice crust, but apparently has at some depth a liquid water ocean which ...
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34 views

Eulerian description of fluid flow

In Eulerian description of fluid flow, we observe how the properties of the fluid are changing at a point. Since a point has zero dimension hence a zero area, how can we make sense of the 'finite ...
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1answer
59 views

Strange simulink error. Professor & TA don't know. Any Ideas?

I am currently working on developing a simulation for a restricted UAV, and I’m having some issues with Simulink while doing this. I have my mathematical equations which have been approved by my ...
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47 views

How does this transformation actually happen?

I cant exactly give you the complete relevant details of the variables but assume the following (bold means vector): B(x) ~ $\frac{1}{8\pi}*(\nabla\frac{1}{r})\times\int \mathbf X'\times \mathbf \...
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48 views

Analytical calculation vs FEA

In terms of calculated stress, strain, displacement etc which method yields more conservative results. Analytical calculation or numeric calculation?
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38 views

Boundary conditions for cantilever beam

I would like to ask about boundary conditions of a cantilever beam with a transverse point (in y dir) load at tip. According to equilibrium equations; We have a normal stress in x direction due to ...
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2answers
64 views

If the turbine drives the compressor, then what limits the engine speed?

My understanding of a typical jet engine is that when running, the turbine extracts energy from the hot exhaust gases. This drives the turbine, which is coupled to the compressor at the front of the ...
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2answers
50 views

Honeycomb structures vs shear stress

Honeycomb structures are made of top and bottom shells and honeycomb geometry at core. In terms of bending load, maximun normal strains take place on top and bottom hence, sheet parts can support them ...
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3answers
65 views

Resonance vs flutter

Is there any difference between resonance and flutter. Both of them are related to overlap of external excitation frequency and Natural frequency then increase in amplitude even inifite amplitude ...
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42 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 * ...
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28 views

Method of Characteristics nozzle - outputs area ratio?

I am designing a rocket engine as my final project at college, and I tried using a MatLab code developed by youtuber JoshTheEngineer. However, after running the code, it seems that the output points ...
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1answer
28 views

Satellite Thruters with reversers

Are there any satellite thrusters that mimic the "thrust reversal" feature of airplanes i.e. (A320...). I already know of procedures to decelerate a satellite such as using two separate thrusters ...
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2answers
85 views

the speed of the exhaust

This is from Stephen Hawking's latest book; Brief Answers to the Big Questions. The speed at which we can send a rocket is governed by two things, the speed of the exhaust and the fraction of its ...
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1answer
27 views

What is the cycle of simulation editing?

So this is very general, but... How are simulations for vehicles done? I know that computational fluid dynamic simulations are used, but why are repeated tests of actual hardware done too? Obviously ...
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1answer
82 views

Why there are no jets (missile or aircraft) faster than Mach 3.3?

Fastest plane ever built: SR-71 ,Max Speed: 3.3 Mach , Development - 1950s Fastest drone ever built: Lockheed-D21 ,Max Speed: 3.3 Mach, Development -1960s Fastest cruise missile ever built: Brahmos ,...
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1answer
48 views

Tethered Balloons vs Towers for Wireless Communication

If we use tethered balloons (aerostats) with wireless gateways fitted on them (let's say for Cellular or LPWAN communication), they can provide much more coverage owing to the height they can reach (e....
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2answers
75 views

Is there an ideal propeller shape?

Are there theories that assert about the ideal shape (i.e., ignoring structural constraints) of a propeller? Just looking at the shapes that emerge in practice, it appears that both the fluid speed ...
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1answer
257 views

Meshing Complex models in abaqus

I'm trying to mesh a model of a morphing wing in Abaqus and have been running into issues. It was recommended that I partition the model into smaller parts, but it seems that the more I try to ...
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1answer
194 views

What is the straightest, longest and strongest pole that could be launched into space?

Which of these poles would be straighter and stronger then the others? These are some poles that are compacted making them possible to send to space. Sending a single solid pole .5km long will not be ...
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0answers
32 views

What does 'Analysis Model Value' in NASTRAN optimization mean?

I am new to MSC NASTRAN and PATRAN. I am running a simulation on composite laminate optimization. While creating the design variables for the study, I noticed that there is a parameter called '...
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1answer
16 views

Contact Motion Analysis (CMA) [closed]

In this solution Helicoptor Fire Control System CMA is used. For motion analysis we use computer vision and image processing. But what is special about CMA.
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2answers
56 views

What is the purpose of building multistage rockets, rather then packing more fuel into a single stage?

Reading an article about multistage rockets (not educated at all on the topic), and from the get go it seems to assume they are used/need to be used.
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1answer
19 views

Vibe Table: Increase Peak Force Capability?

I'm driving a small, benchtop vibe table (shaker) with two Crown DSI-1000 PA's, and also cleaning my signal with a DBX 231s EQ. Currently running the system at 6.8 GRMS, but I'm looking to increase my ...
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1answer
64 views

simulation of an attitude optimal Backstepping controller based quaternion for a UAV in MATLAB

I'am trying to implement this open access research article Attitude Optimal Backstepping Controller Based Quaternion for a UAV I did not find the same result in this paper Can anyone tell me where my ...
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1answer
76 views

Why don't propeller designers use multiple profiles?

I'm designing a ducted fan, and I'm deciding on the airfoil profile. NACA 16-series profiles are well-suited to M > .5 or .6, but they're not particularly efficient at lower Mach numbers. On the other ...
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2answers
346 views

How do solar balloons work at high altitudes?

I am interested in the challenges that Solar Balloons face when flying. For example, the high altitude could cause drastic changes in: Wind speed Temperature Moisture How does the unique design of ...
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1answer
27 views

Calculate attitude quaternion from 2 vector measurements

I am using a method proposed by R. G. Reynolds to estimate attitude based on two vector measurements, taken from: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19990052720.pdf Suppose we ...
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2answers
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Does every engineering design needs to have a complete theoretical backing or may experimental data suffice?

This may sound rather vague on its own so I will explain with examples. The solid booster rockets used by NASA space shuttle used a central bore design because it had a certain characteristic on ...
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2answers
103 views

Need some advice, control system animation. Appreciate some help!

I would like to have a 3d simulation of a helicopter landing on a ship. I thought about using matlab for this, as a far as I know you can connect models from Simulink to virtual worlds using blocks, ...
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1answer
89 views

Would a partial space elevator work? [closed]

Background The normal space elevator (that reaches from the Earth's surface to a counterweight beyond geostationary) needs a material that's strength/weight ratio is better than any material we have ...
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1answer
99 views

How to design the right input to obtain a desired output for a linear system?

If I have a state-space model, so that the A, B, C and D matrices are known, how can I design the right input u, so that y is a custom signal, for example, a sine wave with constant amplitude? $\dot{...
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227 views

Beam element stiffness matrix for variable area cross section with mass and shear center not coinciding

I would like to find the full (12 by 12) Timoshenko beam element stiffness matrix for a variable cross section with mass center axis and elastic center does not coincide. I have the full stiffness ...
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3answers
87 views

Aircraft carrier arresting cables

I recently was at the Naval Air Museum in Pensacola Florida. There are lots of models of aircraft carriers, including the latest class (Gerald Ford class as I recall). This latest class has ...
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0answers
35 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 (...
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2answers
2k views

What is the difference between shaft power and brake power?

I know little about internal combustion engines and I feel a little confused about brake and shaft powers. I read a book that only talks about shaft power, and other that only talks about brake power, ...
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1answer
78 views

What filter is this?

I am implementing a second order filter. It simulates hydraulic servo on an airplane. Its about 35-40 years old. What confuses me is the notation. Like "2(.7)(52)S", what does it mean? If its just ...
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0answers
44 views

Could a Fuel Breathing Engine Rather Than an Oxidizer Breathing Engine Work?

Here on Earth, the atmosphere is ideal for jet engines which combust a fuel using the native oxygen as an oxidizer. On another planet, might it make sense to carry oxidizer in the fuel tanks and scoop ...
3
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1answer
29 views

Development of an interstellar mission: should I design the propulsion system or the main hull of the ship first?

I am currently developing an interstellar mission for a school project. I am thinking whether to design the propulsion system (Bussard scoop) or the main hull and structure of the spaceship first. ...
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2answers
114 views

How do jets/airplane cold start?

If a jet starts in extreme cold, i.e cold starts, then the jet cannot power the heat exchangers to heat the fuel. Then how do they heat the fuel to start the jets? Obviously you can't use batteries/...
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35 views

Given Pitch and Roll in one Heading, convert to co-planar pitch and roll for North

I have been pouring through countless articles about Euler's angles, rotation matrices, Rodriguez Rotation Formula, Quaternions, trying to understand how to generate an algorithm for this problem and ...
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1answer
71 views

Propeller design

I see on internet, that aircraft propellers most effective blades angle only 15 degrees on every blade. Why propellers not use 45 degrees angle on propeller's blade that give more thrust on the ...