How does height affect equation of continuity.
Answers
Answer:
Yes, the equation of continuity is always valid, because otherwise it is implied that mass is being created or destroyed. Even in the case where you have a phase change (e.g. vaporization) or a chemical reaction, continuity would still be valid (as long as you include the relevant terms for the additional phase or chemical species).
In your example, the effect of the orientation of the tube is that when it is vertical, you will have to include a gravitational term in the momentum equation when calculating the velocity. Consider Bernoulli's Equation (for incompressible water, along a streamline):
v22+gz+pρ=constant
When the tube is vertical, the gz term will come into play (z is the height). So, if you have the same pressure drop as the horizontal case, the gravity term will act to increase v. Conversely, to achieve the same v, you wouldn't have to have as much of a pressure drop. Gravity acts in a similar way to pressure on momentum.