on 14-Aug-2018 (Tue)

According to the skilled strategist Sun Tzu, strategy is about winning before the battle begins, while tactics are about striking at weakness.

“Strategy without tactics is the slowest route to victory. Tactics without strategy are the noise before defeat.”

20 CHAPTER 4. LATTICE BOLTZMANN expect that we need a 4 velocity model to fulfill the remaining 4 constraints. But if there was a way to reduce the number of required velocities further we could save some memory and computation time. If you now consider that you will not be interested in the absolute value of the temperature, you can use the determination of the temperature as an additional degree of freedom. You use the 4 equation to determine f 0 −1 , f 0 0 f 1 , and θ.

e know that the velocity has to be much smaller than the lattice velocity c = 1 and θ is nearly constant. Most standard lattice Boltzmann models use these smaller velocity sets. For models in an arbitrary number of dimensions this usually means that the third moment of the equilibrium distribution function is modified to

This description of the simulation of non-ideal fluids is quite superficial. In particular we have only considered the bulk terms of the pressure. There are additional terms which relate to the surface tension. Introducing a forcing of the form of (4.33) will lead to a surface tension

It is important to understand the scoping rules of variables inside functions. Each time a function executes, a new local namespace is created. This represents a local environment that contains the names of the parameters and variables that are assigned by the function. To resolve a namespace when a function is called, the Python interpreter first searches the local namespace (that is, the function itself) and if no match is found, it searches the global namespace. This global namespace is the module in which the function was defined. If the name is still not found, it searches the built-in namespace. Finally, if this fails then the interpreter raises a NameError exception. Consider the following code:
a=10; b=20
def my_function():
global a
a=11; b=21
my_function()
print(a) #prints 11
print(b) #prints 20

Everything is an object in Python, including modules, classes, and functions, as well as literals such as strings and integers

important distinction needs to be made between mutable and immutable objects. Mutable object's such as lists can have their values changed. They have methods, such as insert() or append(), that change an objects value. Immutable objects, such as strings, cannot have their values changed, so when we run their methods, they simply return a value rather than change the value of an underlying object. We can, of course, use this value by assigning it to a variable or using it as an argument in a function