In this blog article, we have compiled ten common fluid mechanics interview questions that a chemical engineering student may encounter during job interviews. These questions cover a range of topics, including fluid properties, fluid flow, pumps, heat exchangers, and boundary layers. We have also provided brief answers to these questions to help students prepare for their interviews and refresh their knowledge of fluid mechanics.
Fluid Mechanics - Interview Question Part 1
Question.1 What is the difference between a fluid and a solid?
A fluid can flow and does not have a definite shape and can take shape of vessel in which it is filled, whereas a solid is rigid and has a definite shape. Also, layers of the fluid will keep on sliding on each other when shear forces applied. Fluids can't resist shear force, solid can.
Question.2 What is the equation of continuity in fluid mechanics?
The equation of continuity is the principle that states that the mass of a fluid that enters a region must equal the mass that exits that region. The equation can be written as A1V1 = A2V2, where A is the area and V is the velocity. The continuity equation is also called mass balance equation.
Question.3 What is the difference between laminar and turbulent flow?
Laminar flow is smooth and ordered, while turbulent flow is chaotic and irregular. Laminar flow is observed at lower Reynolds Number where terbulant flow took place at higher Reynolds Number.
Question.4 What is the Reynolds number, and what does it signify?
The Reynolds number is a dimensionless quantity that represents the ratio of inertial forces to viscous forces. It indicates whether a fluid flow is laminar or turbulent.
Question.5 What is the Navier-Stokes equation?
The Navier-Stokes equation is a set of partial differential equations that describe the motion of a fluid in terms of its velocity, pressure, and density. It is used to solve problems in fluid mechanics.
Question.6 What is the difference between a Newtonian and a non-Newtonian fluid?
A Newtonian fluid has a constant viscosity, while a non-Newtonian fluid's viscosity varies with the applied stress or strain rate. Pseudoplastic, Bingham, Dilantent, and Reheopectic fluids are non-Newtonian fluids.
Question.7 What is the Bernoulli equation, and how is it derived?
The Bernoulli equation is a fundamental equation in fluid mechanics that relates the pressure, velocity, and height of a fluid. It is derived from the principle of conservation of energy. Below is equation of Bernoilli.
Question.8 What is the difference between a pump and a turbine?
A pump is used to increase the pressure of a fluid, while a turbine is used to convert the kinetic energy of a fluid into mechanical energy.
Question.9 What is the purpose of a heat exchanger in fluid systems?
A heat exchanger is used to transfer heat from one fluid to another. It is commonly used to heat or cool fluids in industrial processes. Fluid flow pattern inside heat exchangers are important part of heat exchanger design.
Question.10 What is the difference between laminar and turbulent boundary layers?
The boundary layer is the thin layer of fluid that is in contact with a solid surface. In laminar flow, the boundary layer is smooth and ordered, while in turbulent flow, the boundary layer is chaotic and irregular.