Mechanical Engineering - Hydraulics and Fluid Mechanics - Discussion

Dear @Arun you are wrong.

One dimension does not mean like only in one space coordinates direction(as you say in x).

The direction may change from x to y coordinate direction but it is single.

One dimensional means which only changes w.r.t one space coordinates means it only depends on one coordinate.

A flow in which the streamlines of its moving particles are represent by straight line is called one dimensional flow.

Answer is D because straight line does not mean that it is flowing only in one direction.

1 D flow takes place in one direction only. So the correct answer is D.

The single space coordinate is usually the distance measured along the center-line (not necessarily straight) in which the fluid is flowing.

Example: The flow in a pipe is considered one-dimensional when variations of pressure and velocity occur along the length of the pipe, but any variation over the cross-section is assumed negligible.

In reality, flow is never one-dimensional because viscosity causes the velocity to decrease to zero at the solid boundaries.

If the flow of fluid in one direction only, which is called one dimensional flow (i.e. mostly flows in x-direction). Option D is correct.

If pressure and velocity vary in one dimensional flow then pv remained constant as it graph shows. The straight line from origin. Usually fluid flowing in a pipe considered one dimensional flow. I hope it's something which make you understand.

I think both the option B and D are correct.

Answer B & D are correct because as it indicates one dimensional flow.