test_zero_flow_closures Namespace Reference

Functions
object	_pipe (str tag, float length=1.0)
object	_checked (float drop_psi)
None	test_a_check_valve_below_its_cracking_pressure_is_shut (float drop_psi)
None	test_a_check_valve_past_its_cracking_pressure_flows (float drop_psi)
object	_regulated (float tank_psia, float rise_psi)
None	test_a_regulator_inside_its_lockup_rise_solves (float tank_psia)
object	_regulator (float rise_psi)
None	test_the_rise_is_continuous_across_zero_flow ()
None	test_with_no_rise_a_regulator_is_what_it_was (float mdot)

Variables
float	PSI = 6894.757293168361
	M = Provenance.MEASURED

Detailed Description

A one-way device between zero flow and its opening pressure is shut.

A check valve's cracking pressure and a regulator's lockup rise both step the
branch relation at zero flow. With the far side inside that step there was no
root -- forward needed at least the step, reverse at most nothing -- and every
solve failed, which is exactly where a tank pressed through a check valve, or
held by a regulator at lockup, comes to rest. Inside the step the device is
shut: zero flow, the pressures either side free.

Function Documentation

_checked()

object test_zero_flow_closures._checked ( float drop_psi )

protected

A -> pipe -> check valve (3 psi crack) -> pipe -> B, ``drop_psi`` apart.

Definition at line 38 of file test_zero_flow_closures.py.

References _pipe().

Referenced by test_a_check_valve_below_its_cracking_pressure_is_shut(), and test_a_check_valve_past_its_cracking_pressure_flows().

_pipe()

object test_zero_flow_closures._pipe ( str tag, float length = 1.0 )

protected

Definition at line 24 of file test_zero_flow_closures.py.

Referenced by _checked(), and _regulated().

_regulated()

object test_zero_flow_closures._regulated ( float tank_psia, float rise_psi )

protected

3000 psia bottle -> regulator (500 psia, 20 psi droop at 0.05 kg/s,
``rise_psi`` of lockup rise) -> pipe -> a tank held at ``tank_psia``.

Definition at line 79 of file test_zero_flow_closures.py.

References _pipe().

Referenced by test_a_regulator_inside_its_lockup_rise_solves().

_regulator()

object test_zero_flow_closures._regulator ( float rise_psi )

protected

Definition at line 124 of file test_zero_flow_closures.py.

Referenced by test_the_rise_is_continuous_across_zero_flow(), and test_with_no_rise_a_regulator_is_what_it_was().

test_a_check_valve_below_its_cracking_pressure_is_shut()

None test_zero_flow_closures.test_a_check_valve_below_its_cracking_pressure_is_shut

(

float

drop_psi

)

Definition at line 66 of file test_zero_flow_closures.py.

References _checked().

test_a_check_valve_past_its_cracking_pressure_flows()

None test_zero_flow_closures.test_a_check_valve_past_its_cracking_pressure_flows

(

float

drop_psi

)

Definition at line 73 of file test_zero_flow_closures.py.

References _checked().

test_a_regulator_inside_its_lockup_rise_solves()

None test_zero_flow_closures.test_a_regulator_inside_its_lockup_rise_solves

(

float

tank_psia

)

5 psi of rise on a 500 psia setpoint: a tank anywhere from below the
setpoint to past lockup has an answer. 500.5-502.4 psia had none. The flow
falls to nothing as the tank comes up to lockup (505 psia).

Definition at line 111 of file test_zero_flow_closures.py.

References _regulated().

test_the_rise_is_continuous_across_zero_flow()

None test_zero_flow_closures.test_the_rise_is_continuous_across_zero_flow

(

)

Lockup (set + rise) at zero flow, the droop line once the rise is paid
back, and no step between: the rise is lost at the droop's own rate.

Definition at line 142 of file test_zero_flow_closures.py.

References _regulator().

test_with_no_rise_a_regulator_is_what_it_was()

None test_zero_flow_closures.test_with_no_rise_a_regulator_is_what_it_was

(

float

mdot

)

The closure changes nothing for a regulator that declares no rise (the
study drawings, LE4): outlet = set - droop m / rated, shut above it.

Definition at line 158 of file test_zero_flow_closures.py.

References _regulator().

Variable Documentation

M

test_zero_flow_closures.M = Provenance.MEASURED

Definition at line 21 of file test_zero_flow_closures.py.

PSI

float test_zero_flow_closures.PSI = 6894.757293168361

Definition at line 20 of file test_zero_flow_closures.py.