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.

Filter by
Sorted by
Tagged with
0
votes
0answers
12 views

Feasibility of additively manufacturing large metal objects in microgravity/high vacuum (space)

This a somewhat speculative question; I would like to know whether it is feasible to additively manufacture large (>100m) metal objects - from for example aluminum alloys - in a space environment. ...
1
vote
1answer
32 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 ...
0
votes
1answer
21 views

Pressure Coefficient with a Minima of 0 on Compressor Airfoils in Cascade

I am a relatively recent BSME graduate working on reproducing the results of a technical paper to strengthen my ANSYS CFX skills. The paper is "Effect of Section Thickness and Trailing Edge Radius on ...
1
vote
0answers
31 views

What propulsion method: Franky Zapata hoverboard

Looking for the answer to what kind of engine provides the thrust on the French hoverboard on which its inventor, Franky Zapata, recently crossed the English Channel, I find the same phrase repeated ...
0
votes
0answers
15 views

Question with regard to spacex raptor engineand other full flow staged combustion engines

The diagram linked is unofficial but I've looked at other diagrams which are similar. The coolant is pumped in at a high pressure much higher than the maximum chamber pressure of the rocket the ...
1
vote
2answers
70 views

What happened to the projectile in Hypervelocity Impact tests?

I recently saw a tweet about Hypervelocity Impact Sample and someone ask how is it possible to shoot a projectile at that speed and what happened to the used projectile when hitting the shield. I ...
0
votes
2answers
75 views

What should be the material and thickness of front pillars to stop car (~1,847kg and ~262 km/h) without killing the driver?

"Tesla Model 3 owner died in a tragic accident with a semi truck. The Model 3 went under the truck’s trailer resulting “in the roof being sheared off as it passed underneath,” which is known as a “...
1
vote
2answers
108 views

What does it mean that the mass of a propellant tank is at premium?

I am reading the rocket propulsion elements book by sutton and I came across the following statement: "Because the propellant tank has to fly. its mass is at a premium and the tank material is ...
1
vote
0answers
15 views

How to minimize temperature increase caused by compression of a cryogenic liquid in a multistage high pressure turbopump?

The cryogenic fuel I'm using is methane at 100 K and 300,000 Pa. Based on my calculations, after compression, the pressure is 55 MPa and using the ideal gas equation the temperature is approx. 800 K. ...
2
votes
1answer
45 views

Closed loop guidance and control: how to tune a system with multiple feedback controllers?

I'm trying to design a closed-loop guidance system for rockets - something that can be implemented in Kerbal Space Program, for example. To do this, I'm following the design process described in ...
0
votes
1answer
13 views

Relationships among turbo jet rpm and compression ratio and thrust

A question about performance of a turbojet. Why are compression ratio and thrust are not in linear but increase exponentially with RPM?
0
votes
2answers
56 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 ...
2
votes
1answer
85 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
votes
3answers
130 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 ...
0
votes
1answer
63 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 ...
1
vote
0answers
51 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 ...
0
votes
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_{...
0
votes
0answers
43 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 ...
1
vote
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 ...
2
votes
0answers
38 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 ...
1
vote
1answer
63 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 ...
0
votes
0answers
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 \...
0
votes
0answers
53 views

Analytical calculation vs FEA

In terms of calculated stress, strain, displacement etc which method yields more conservative results. Analytical calculation or numeric calculation?
0
votes
0answers
52 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 ...
0
votes
2answers
66 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 ...
2
votes
2answers
59 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 ...
2
votes
3answers
82 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 ...
0
votes
0answers
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 * ...
0
votes
0answers
31 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 ...
1
vote
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 ...
1
vote
2answers
86 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 ...
1
vote
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 ...
1
vote
1answer
84 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 ,...
1
vote
1answer
50 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....
0
votes
2answers
81 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 ...
1
vote
1answer
302 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 ...
1
vote
1answer
200 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 ...
1
vote
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 '...
0
votes
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.
3
votes
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.
0
votes
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 ...
1
vote
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 ...
5
votes
1answer
81 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 ...
2
votes
2answers
348 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 ...
0
votes
1answer
29 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 ...
6
votes
2answers
81 views

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 ...
4
votes
2answers
108 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, ...
5
votes
1answer
92 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 ...
3
votes
1answer
100 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{...
1
vote
0answers
242 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 ...