Introduction of background knowledge regarding flow physics and CFD as well as detailed information about the use of AcuSolve and what specific options do.
This section on basics of fluid mechanics covers topics describing the fundamental concepts of fluid mechanics, such as
the concept of continuum, the governing equations of a fluid flow, definition of similitude and importance of non-dimensional
numbers, different types of flow models and boundary layer theory.
This section on turbulence covers the topics describing the physics of turbulence and turbulent flow. It also covers the
modeling of turbulence with brief descriptions of commonly used turbulence models.
This section on physics of turbulence introduces a brief history of turbulence and covers the theory behind turbulence
generation, turbulence transition and energy cascade in fluid flows.
The Reynolds number is not only used to characterize the flow patterns, such as laminar or turbulent flow, but also to
determine the dynamic similitude between two different flow cases.
The physics of turbulent flows have been discussed by presenting experimental observations and comparing it to laminar
flows. In this chapter, the focus will shift to the governing equations of these flow fields.
Turbulence is composed of turbulent eddies of different sizes. At high Reynolds numbers, a scale separation exists between
the largest eddies and smallest eddies.
This section covers the numerical modeling of turbulence by various turbulence models, near wall modeling and inlet turbulence
parameters specified for turbulence models.
This section on numerical approximation techniques covers topics, which describe the numerical modeling of the fluid flow
equations on a computational domain, such as spatial discretization using finite difference, finite element and finite volume
techniques, temporal discretization and solution methods.
This section on AcuSolve solver features covers the description of various solver features available in AcuSolve such as heat transfer, fluid structure interaction and turbulence modeling.
Collection of AcuSolve simulation cases for which results are compared against analytical or experimental results to demonstrate the accuracy
of AcuSolve results.
Introduction of background knowledge regarding flow physics and CFD as well as detailed information about the use of AcuSolve and what specific options do.
This section on turbulence covers the topics describing the physics of turbulence and turbulent flow. It also covers the
modeling of turbulence with brief descriptions of commonly used turbulence models.
This section on physics of turbulence introduces a brief history of turbulence and covers the theory behind turbulence
generation, turbulence transition and energy cascade in fluid flows.
Leonardo da Vinci was the first one to report the visualization of turbulent flow in his
famous sketches from 1510.
He described the existence of whirlpools of water in his notes. He wrote, “Observe the motion
of the surface of the water, which resembles that of hair, which has two motions, of which one
is caused by the weight of the hair, the other by the direction of the curls; thus the water
has eddying motions, one part of which is due to the principal current, the other to random
and reverse motion.” This notion is a precursor to the Reynolds flow decomposition of velocity
into mean and fluctuating parts, which Osborne Reynolds suggested 400 years later. He also
noted, “The small eddies are almost numberless, and large things are rotated only by large
eddies and not by small ones and small things are turned by both small eddies and large.”
Nowadays, the “small eddies” and the “large things” refer to turbulence and large-scale
coherent eddies, respectively. Leonardo da Vinci utilized his sketches as a flow visualization
method, providing clear information of turbulence behaviors and their effects.