GopherProxy

	tClass with all relevant parameters. Needs IO - ns2dfd - 2D finite difference N…
	git clone git://src.adamsgaard.dk/ns2dfd
	Log
	Files
	Refs
	LICENSE
	---
	commit 02907fc07a66c16364379dbf5d92550083ce0730
	Author: Anders Damsgaard <[email protected]>
	Date: Sat, 1 Mar 2014 17:25:56 +0100

	Class with all relevant parameters. Needs IO

	Diffstat:
	A ns2dfd.py \| 137 +++++++++++++++++++++++++++++…

	1 file changed, 137 insertions(+), 0 deletions(-)
	---
	diff --git a/ns2dfd.py b/ns2dfd.py
	t@@ -0,0 +1,137 @@
	+#!/usr/bin/env python
	+
	+import numpy
	+
	+class fluid:
	+
	+ def __init__(sim = 'unnamed'):
	+ '''
	+ A Navier-Stokes two-dimensional fluid flow simulation object. Most
	+ simulation values are assigned default values upon initialization.
	+ :param sim: Simulation identifier
	+ :type sim: str
	+ '''
	+ self.sim = sim
	+
	+ init_grid()
	+ current_time()
	+ safety_factor()
	+ max_iterations()
	+ tolerance_criteria()
	+ relaxation_parameter()
	+ upwind_differencing_factor()
	+ boundary_conditions()
	+ reynolds_number()
	+ gravity()
	+
	+ def init_grid(nx = 10, ny = 10, dx = 0.1, dy = 0.1):
	+ '''
	+ Initializes the numerical grid.
	+ :param nx: Fluid grid width in number of cells
	+ :type nx: int
	+ :param ny: Fluid grid height in number of cells
	+ :type ny: int
	+ :param dx: Grid cell width (meters)
	+ :type dx: float
	+ :param dy: Grid cell height (meters)
	+ :type dy: float
	+ '''
	+ self.nx, self.ny = nx, ny
	+ self.dx, self.dy = dx, dy
	+ self.u = numpy.zeros((nx+2, ny+2))
	+ self.v = numpy.zeros((nx+2, ny+2))
	+ self.p = numpy.zeros((nx+1, ny+1))
	+
	+ def current_time(t = 0.0):
	+ '''
	+ Set the current simulation time. Default value = 0.0.
	+ :param t: The current time value.
	+ :type t: float
	+ '''
	+ self.t_end = t_end
	+
	+
	+ def end_time(t_end):
	+ '''
	+ Set the simulation end time.
	+ :param t_end: The time when to stop the simulation.
	+ :type t_end: float
	+ '''
	+ self.t_end = t_end
	+
	+ def safety_factor(tau = 0.5):
	+ '''
	+ Define the safety factor for the time step size control. Default value…
	+ 0.5.
	+ :param tau: Safety factor in ]0;1]
	+ :type tau: float
	+ '''
	+ self.tau = tau
	+
	+ def max_iterations(itermax = 5000):
	+ '''
	+ Set the maximal allowed iterations per time step. Default value = 5000.
	+ :param itermax: Max. solution iterations in [1;inf[
	+ :type itermax: int
	+ '''
	+ self.itermax = itermax
	+
	+ def tolerance_criteria(epsilon = 1.0e-4):
	+ '''
	+ Set the tolerance criteria for the fluid solver. Default value = 1.0e-…
	+ :param epsilon: Criteria value
	+ :type epsilon: float
	+ '''
	+ self.epsilon = epsilon
	+
	+ def relaxation_parameter(omega = 1.7):
	+ '''
	+ Set the relaxation parameter for the successive overrelaxation (SOR)
	+ solver. The solver is identical to the Gauss-Seidel method when omega =
	+ 1. Default value = 1.7.
	+ :param omega: Relaxation parameter value, in ]0;2[
	+ :type omega: float
	+ '''
	+ self.omega = omega
	+
	+ def upwind_differencing_factor(gamma = 0.9):
	+ '''
	+ Set the upwind diffencing factor used in the finite difference
	+ approximations. Default value = 0.9.
	+ :param gamma: Upward differencing factor value, in ]0;1[
	+ :type gamma: float
	+ '''
	+ self.gamma = gamma
	+
	+ def boundary_conditions(left = 1, right = 1, top = 1, bottom = 1):
	+ '''
	+ Set the wall boundary conditions. The values correspond to the followi…
	+ conditions: 1) free-slip, 2) no-slip, 3) outflow, 4) periodic
	+ :param left, right, top, bottom: The wall to specify the BC for
	+ :type left, right, top, bottom: int
	+ '''
	+ self.w_left = left
	+ self.w_right = right
	+ self.w_top = top
	+ self.w_bottom = bottom
	+
	+ def reynolds_number(re = 100):
	+ '''
	+ Define the simulation Reynolds number.
	+ :param re: Reynolds number in ]0;infty[
	+ :type re: float
	+ '''
	+ self.re = re
	+
	+ def gravity(gx = 0.0, gy = 0.0):
	+ '''
	+ Set the gravitational acceleration on the fluid.
	+ :param gx: Horizontal gravitational acceleration.
	+ :type gx: float
	+ :param gy: Vertical gravitational acceleration. Negative values are
	+ downward.
	+ :type gy: float
	+ '''
	+ self.gx, self.gy = gx, gy
	+
	+