# fluid mechanics

— fluid dynamics / fluid mechanics

• Everything is Fluid Mechanics and Navier-Stokes equations — Chris Rogers, Tufts Center for Engineering Education and Outreach

Fluid Mechanics – science of fluids at rest or in motion in aeronautics, chemical, civil, and mechanical engineering, meteorology, naval architecture, and oceanography.

Fluid mechanics or fluid dynamics is the study of the macroscopic physical behaviour of fluids . Fluids are specifically liquids and gases though some other materials and systems can be described in a similar way. The solution of a fluid dynamic problem typically involves calculating for various properties of the fluid, such as velocity, pressure, density, and temperature, as functions of space and time. The discipline has a number of subdisciplines, including aerodynamics (the study of gases) and hydrodynamics (the study of liquids). Fluid mechanics has a wide range of applications. For example, it is used in calculating forces and moments on aircraft, the mass flow of petroleum through pipelines, and in prediction of weather patterns, and even in traffic engineering, where traffic is treated as a continuous flowing fluid.

• hydrodynamics (study of liquids in motion). Often used synonymously with fluid dynamics, since most of the results from the study of liquids also apply to gases
• aerodynamics (study of gases in motion)

Applications of fluid mechanics involve all kinds of flow machinery, including jet propulsion, hydraulics, turbine, compressors, and pumps. Hydraulics mainly concerns machines and structures such as hydraulic turbines, dams, and hydraulic pressures, using water or other liquids.

Some fluid dynamics that you might not have thought about

• artificial heart valves are plagued with complications associated with haemolysis, coagulation for mechanical heart valves and leaflet tearing for tissue-based valve prosthesis. For mechanical heart valves, these complications are believed to be associated with non-physiological blood flow patterns. Study continues into fluid mechanics for the major artificial heart valve types and how the engineering approach has shaped this rapidly diversifying area of research.

Navier-Stokes equations describe the motion of fluid substances. The equations are useful because they describe the physics of many things – the weather, ocean currents, water flow in a pipe and air flow around a wing. The Navier–Stokes equations help with the design of aircraft and cars, the study of blood flow, the design of power stations, the analysis of pollution, and many other things. The Navier–Stokes equations are used extensively in video games in order to model a wide variety of natural phenomena, such as fire and smoke.

Viscosity

Turbulence –

Calculus, specifically nonlinear partial differential equations, is essential to understanding fluid mechanics. Navier–Stokes equations are nonlinear partial differential equations in almost every real situation.

Conservation of mass https://www.grc.nasa.gov/WWW/k-12/airplane/mass.html

Surf’s up – What’s the problem?

Wavegarden (video) is an engineering company that designs and manufactures wave generating systems and lagoons for surfing and other watersports. The Wavegarden team of engineering experts specialized in mechanical and aerodynamic systems -all of them passionate surfers- has worked for nearly a decade to create an artificial surfing lagoon designed to generate consistent, perfectly formed waves for surfers of all abilities.

• Ask – What makes a perfect wave? How can this be simulated away from an ocean?
• Imagine – Wavegarden’s patented technology is based on an innovative hydrodynamic Wavefoil and a revolutionary wave lagoon design.
• Plan, Create – The state of the art Wavefoil generator has been proved to be more reliable and to require significantly less energy compared to other artificial wave technologies
• Improve

That’s engineering

• coagulate – to congeal; to solidify, set, gel; to thicken; to clot

Engineering ideas

• viscosity, fluid, drag force, flow rate, fluid motion, stress, pressure, gradient, calculus, differential equations, turbulence

Do it
Here are some challenges for you to work on…

• Engineer a Vortex Powered Jellyfishvortex (video 7:28) – Design and build a model jellyfish that can create a vortex current and cause sinking objects to rise to the top of a body of water. A jellyfish uses jet propulsion to push itself forward in the water by opening and closing its bell (the circular part of the animal) – very similarly to how you open and close an umbrella.