Recent content by aero&astro

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    Question about grad, nabla (vector operator)

    In my notes it says that grad F will give you a vector normal to the contour. Howver I thought grad F would give you a vector tangent because the path is aligned with the vector field. Is it different when talking about contours and paths? If you find grad F of a function F does that give...
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    Why do we use the distance to the centroid when finding the resultant force?

    there's always two different values for the distance to the centre of pressure and to the centroid though?
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    When to consider yielding vs. rupture as a mode of failure?

    it won't buckle at the yield strength, the yield strength denotes the onset of plastic deformation. failure only occurs at the UTS. In that sense I don't think yielding can ever be considered a failure mode. It can lead to things like fatigue which is a failure mode due to cyclic loading and...
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    How do I determine torque required to accelerate

    you can calculate the second moment of area for each shape then moment of inertia = mass per unit area x second moment of area second moment of area for a triangle is bh^3 / 36 for a rectangle is bd^3 / 12 for a semis circle its 0.1102 R^4 then all you need to do is use the moment of inertia...
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    Why do we use the distance to the centroid when finding the resultant force?

    When find the resultant force on a plane surface under uniform pressure why do we use ybar, the distance to the centroid when the resultant force acts through the centre of pressure? Shouldn't we use the distance to the centre of pressure?
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    Are there user-friendly mechanism design softwares available?

    SolidWorks maybe, but still there's no easy way around CAD
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    Velocity profile and streamline equations, help please?

    So far I know that dy/dx = V/U is the velocity profile. From what I've read if you know V & U and put it into that equation and the integrate it you get the equation of a streamline. is this correct? An example I have is of a velocity field defined by |U| = (B+Ay^2)e_1. The graph of the...
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    Simple question about object submerged in a fluid (fluid Mechanics)

    If an object like a sphere is submerged in a fluid and held in place by a rope, does the pressure are the top and the bottom of the sphere have anything to do with the weight/density/geometery of the sphere? or is it simply a case of using the hydrostatic equation for the pressure at the top and...
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    Take-off Lift coefficient for the A380 or other very long range airliners?

    Does anyone know what the take off life coefficient for very-long range airliners might be in general or where i could find this kind of information? I'm doing some calculations on things like aspect ratio, landing lift coefficient etc for a report on aircraft design. My results are...
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    MEng in Mechanical Engineering/Aerospace Engineering

    It is totally possible, I'm doing it now
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    Propeller Design Software?

    solid works or flow works maybe?
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    Why Does a Spitfire Yaw During Takeoff? | Exploring the Gyroscopic Effect

    I'm looking for four or five reasons why aircraft like the Spitfire tend to yaw during take off. I know the gyroscopic effect is one, but I don't know why or even what this is. Can anyone help?
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    Motion of an object submerged in water.

    thanks a lot guys, this really helped.
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    Motion of an object submerged in water.

    why is it Fup - Fdown and not Fdown - Fup?
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    Motion of an object submerged in water.

    ignoring drag, how could you describe the motion of a cylindrical object in water, if the upwards buoyancy force is given by a certain equation? (B = [1020+0.25z]Volumexgravity) I'm not sure if its just Fup = Fdown where Fdown is the weight and Fup is the buoyancy. However it can't be that or...
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