Recent content by aerograce

I encountered this statement on my lecture notes today, I don't understand why compressible flow needs to have another constraint of energy equation while incompressible flow only satisfies continuity and momentum equation. And how is this energy equation related to the speed of sound?

Thank you! I am looking it up, seems useful!

Sure. This torsional balance is able to rotate around the pivot axis, and the pivot is basically a torsional spring. Thruster is mounted at one side of the torsional balance and the counterweight is used to balance the two arms to make sure it stays in horizontal plane. When thrust force is...

I have constructed a torsional balance, which basically consists of a torsional spring, and a damper. I model this as a spring mass damper system. And it is used to measure thrust of some propulsion system. This is how the system looks like. I am just very eager to find out, how to model the...

I am pretty confused about how to write Navier-Stokes Equation into conservation form, it seems that from my notes, first, the density term with the pressure gradient dropped out. and second, du^2/dx seems to be equal to udu/dx. Why is it so? I attached my notes here for your reference.

I am intending to design a CD nozzle that produces 20mN thrust under atmospheric conditions. The reservoir pressure will be 1.4 bar, and the ambient pressure will be 1 bar. The other variables are adjustable. This will in the end be sent out for fabrication.My process is as follow, May I know...

Homework Statement A hemispherical cavity of radius 1.0 m is covered with a plate having an opening of 0.2 m diameter drilled at its centre. The inner surface of the plate is maintained at 700 K by a heater embedded in the surface. Let the inner surface of the plate be 1, the surface of the...

May I know, when writing the rotational equilibrium equation, should I list moment equilibrium about its center of gravity? I am confused because since center of gravity of the link AB is not a fixed point, if write moment equilibrium about its center of gravity, the angular acceleration has to...

Hello. I have drawn free body diagram as follow. The horizontal acceleration of a will be α*R. And this acceleration can be related to point B with formula [/B]=[a] + w×(w×[r][/(B/A)]+w'×[r][/(B/A)]. But I think when I write down equations, I discover too many unknowns to be solved. Could you...

Homework Statement A uniform rod AB of length L and mass m1 is connected by a pin joint to the center of a uniform disc of radius R and mass m2. The system is placed in a vertical plane (as shown in Figure 2) and released from rest with θ=45°. (a) Draw the free-body diagrams for the rod and the...

Thank you so much!:)

Hello! Sorry for my late reply. I can't seem to get the forces acting on mT. The force acting on mT will be gravity, and then force caused by pivot stiffness, and then thrust. However, I can't seem to catch the meaning of that moment inertia * angular acceleration over arm length, isn't it...

Homework Statement Hi guys! I am reading a paper on inverted pendulum. However, I can't understand the dynamics equations of this inverted pendulum. You may look at the images below. Basically the thruster is placed at top plate, while the middle plate is a base plate where pivot is placed. And...

I'm doing initial design. I need some theoretical validation of my model:)

I am doing a school project, building a compressed air powered vehicle to reach desired destination. What I am thinking is: I will use a paintball compressed air tank. Four nozzles. And an controller board to control valve opening. Valve will only open for certain time like (50ms). After each...