"When interviewing candidates for the role of mechanical engineer, employers look for candidates who are enthusiastic to create innovative designs, analyses, and methods of production for mechanical systems. Expect to answer engineering questions that will assess your knowledge of the field as well as your creative problem-solving abilities to turn a theoretical device into a real product. In addition, come ready to discuss examples of past projects or designs and how you would excel in a team-oriented setting."
How do you determine the direction of fluid flow in a pipe without directly interacting with what's inside?
Measure temperature, noise, etc.
Relative height of two ends
Measure the longitudinal strain at two points along the path of the pipe. The flow direction will be from highest to lowest strain. Measures shear stress. Measure lateral strain like longitudinal strain, associated with fluid pressure. Pressure gradient will be from high strain to low strain.