Fluid Mechanics
Fluid Mechanics is a foundational course that deals with the basic properties of fluids, hydrostatics, fluid kinematics, control volume and differential analysis, dimensional analysis, internal/external flow, turbomachines, water hammer and introduction to compressible flow with an engineering approach.
Course Content
ChaptersBasic properties such as fluid concept, continuum approach, density, specific gravity, specific volume, viscosity, surface tension and vapor pressure are discussed. The difference between fluids and solids, Newtonian and non-Newtonian fluid behavior, and the selection of appropriate properties in engineering problems are interpreted physically.
Pressure change, manometers, hydrostatic forces and buoyancy in stationary fluids are examined. Pressure force acting on planar and curvilinear surfaces, center of pressure, balance of floating objects and hydrostatic applications are discussed through worked examples and problem solving. Within the scope of fluids in rigid body motion, pressure distribution, free surface shape and liquid rise problems in a container/vehicle with linear acceleration and rotational motion are also studied.
Fluid movement; Eulerian and Lagrangian approaches are examined through the concepts of velocity field, acceleration field, streamline, pathline, streakline, system and control volume. The concepts of steady-unsteady flow, uniform and nonuniform flow, one/two/three-dimensional flow, rotational and irrotational flow and flow visualization are discussed. The concept of streamline is associated with the physical interpretation of the Bernoulli equation and it is shown how changes in velocity, pressure and height are evaluated throughout the flow.
Mass, momentum and energy balances are established in fluid systems using the control volume approach. The relationship between the system approach and the control volume approach is explained through Reynolds Transport Theorem (RTT). In the standard course sequence, the control volume form of the continuity, momentum and energy equations is obtained based on RTT. The detailed derivation of RTT is handled optionally according to the needs of the student. Appropriate control volume selection and physical interpretation of equations in nozzle, diffuser, pipe, elbow, jet and fluid force problems are studied.
The flow field is studied with the differential element approach. Differential forms of continuity, momentum and energy equations are interpreted by making connections with integral equations obtained from Reynolds Transport Theorem. The basic structure of the Euler equations and the Navier–Stokes equations, their physical meaning, and their relationship to viscous effects are discussed. It is shown how the Bernoulli equation is derived from the Euler equations under suitable conditions where viscous effects are neglected. Couette flow, Poiseuille flow and simple channel/pipe flow examples are studied through worked examples and problem solving within the scope of some specific and approximate solutions of the Navier–Stokes equations.
Dimensional analysis, Buckingham Pi theorem, and the physical meaning of dimensionless numbers are discussed. Fundamental dimensionless parameters such as Reynolds, Froude, Mach, Weber and Euler numbers are associated with fluid mechanics problems. Model-prototype similarity, geometric/kinematic/dynamic similarity and experimental data interpretation worked examples and problem solving are studied.
Laminar and turbulent flow regimes, Reynolds number, advanced flow, friction factor and head losses are examined in in-pipe flows. Darcy–Weisbach equation, Moody diagram, minor losses, series–parallel pipe systems and pump-assisted flow problems are addressed through worked examples and problem solving.
External flow around submerged objects is examined through the concept of boundary layer, drag and lift forces. Pressure drag, friction drag, separation and wake formation in flows around flat plates, cylinders, spheres and airfoils are interpreted physically. Aerodynamic coefficients and experimental correlations are discussed at a fundamental level.
Pumps, turbines, fans and compressors are examined within the framework of turbomachinery principles. Euler turbomachine equation, specific speed, pump characteristic curves, system curve, operating point, efficiency and power calculation are studied with worked examples and problem solving. Engineering criteria such as flow rate, head, system curve, operating point, NPSH and cavitation risk are considered in pump selection. The relationship of turbomachines with fluid mechanics, energy conversion and engineering applications is interpreted.
Temporary pressure waves that occur in pipe systems as a result of sudden valve closing or rapid changes in flow rate are examined through the concept of water hammer. Joukowsky pressure rise, wave velocity, pipe elasticity, fluid compressibility and the physical meaning of pressure oscillations are discussed at a basic level. The engineering importance of water hammer in pump-valve-pipe systems and simple prevention approaches are discussed.
Basic concepts of compressible flow; Mach number, speed of sound, stagnation properties and the effect of density change on flow behavior are examined. Isentropic flow relationships, velocity-pressure-temperature changes in nozzles and diffusers, and the concept of suffocation are discussed at a basic level. This chapter creates the fluid mechanics background for moving on to detailed gas dynamics topics.
Targeted Learning Outcomes
- Physically interpret the concepts of fluid properties, pressure distribution, hydrostatic force and buoyancy.
- Mathematically and physically represent flow motion by using Eulerian–Lagrangian approaches in fluid kinematics, the concepts of velocity field, acceleration field, streamline, pathline and streakline.
- Interpret the Bernoulli equation as the mechanical energy balance between the terms pressure, velocity and height along the streamline and establish mass, momentum and energy equations using Reynolds Transport Theorem and control volume approach.
- Interpret the physical meaning of Euler and Navier–Stokes equations in differential flow analysis and to make the relevant assumptions and obtain approximate solutions.
- Use the principles of dimensional analysis, similarity and experimental modeling in fluid mechanics problems.
- Choose the appropriate model and make physical interpretations of internal flow, external flow, turbomachinery, water hammer and compressible flow problems.