test_branch_direction Namespace Reference

Functions
object	_valve ()
object	_pipe ()
float	_flow (float tank_psia, bool drawn_with_the_flow, object part)
None	test_a_valve_drawn_either_way_passes_the_same_flow (float tank_psia)
None	test_reverse_flow_chokes_like_forward_flow ()
None	test_a_gas_pipe_drawn_either_way_passes_the_same_flow ()
None	test_a_check_valve_keeps_its_drawn_direction ()

Variables
float	PSI = 6894.757293168361
	M = Provenance.MANUFACTURER

Detailed Description

A symmetric component does not care which way it was drawn.

pid-designer reads a symbol's in/out from its left/right ports, so a vent or
press solenoid placed mirrored is a branch drawn against its flow. The solve
used to price every branch at its drawn upstream node -- the low-pressure end
when the flow runs backwards -- and never let reverse flow choke: a Cv 4 valve
on 3000 psia nitrogen to atmosphere passed 3.81 kg/s drawn with the flow and
0.47 drawn against it, both converged.

One-way laws keep their drawn direction: a check valve, a regulator, a relief.

Function Documentation

_flow()

float test_branch_direction._flow ( float tank_psia, bool drawn_with_the_flow, object part )

protected

A gas tank to atmosphere through one component, drawn either way.
Returned as the flow out of the tank.

Definition at line 46 of file test_branch_direction.py.

Referenced by test_a_gas_pipe_drawn_either_way_passes_the_same_flow(), and test_a_valve_drawn_either_way_passes_the_same_flow().

_pipe()

object test_branch_direction._pipe ( )

protected

Definition at line 36 of file test_branch_direction.py.

Referenced by test_a_gas_pipe_drawn_either_way_passes_the_same_flow().

_valve()

object test_branch_direction._valve ( )

protected

Definition at line 26 of file test_branch_direction.py.

Referenced by test_a_check_valve_keeps_its_drawn_direction(), test_a_valve_drawn_either_way_passes_the_same_flow(), and test_reverse_flow_chokes_like_forward_flow().

test_a_check_valve_keeps_its_drawn_direction()

None test_branch_direction.test_a_check_valve_keeps_its_drawn_direction

(

)

Drawn against the gradient it holds: a one-way law is not mirrored.

Definition at line 93 of file test_branch_direction.py.

References _valve().

test_a_gas_pipe_drawn_either_way_passes_the_same_flow()

None test_branch_direction.test_a_gas_pipe_drawn_either_way_passes_the_same_flow

(

)

Definition at line 87 of file test_branch_direction.py.

References _flow(), and _pipe().

test_a_valve_drawn_either_way_passes_the_same_flow()

None test_branch_direction.test_a_valve_drawn_either_way_passes_the_same_flow

(

float

tank_psia

)

Definition at line 64 of file test_branch_direction.py.

References _flow(), and _valve().

test_reverse_flow_chokes_like_forward_flow()

None test_branch_direction.test_reverse_flow_chokes_like_forward_flow

(

)

3000 psia to atmosphere is far past the critical ratio either way.

Definition at line 71 of file test_branch_direction.py.

References _valve().

Variable Documentation

M

test_branch_direction.M = Provenance.MANUFACTURER

Definition at line 23 of file test_branch_direction.py.

PSI

float test_branch_direction.PSI = 6894.757293168361

Definition at line 22 of file test_branch_direction.py.