test_wall.TestExchange Class Reference

Public Member Functions
None	test_no_flow_no_heat (self)
None	test_warm_wall_warms_cold_gas (self)
None	test_cold_wall_cools_warm_gas (self)
None	test_gas_never_overshoots_the_wall (self)
None	test_more_flow_means_less_warming_per_kilogram (self)
None	test_more_metal_area_means_more_pickup (self)
None	test_heat_agrees_with_the_temperature_rise (self)
None	test_reverse_flow_is_treated_by_magnitude (self)
None	test_laminar_uses_a_fixed_nusselt (self)
None	test_missing_property_is_not_a_crash (self, str bad)

Detailed Description

Definition at line 74 of file test_wall.py.

Member Function Documentation

test_cold_wall_cools_warm_gas()

None test_wall.TestExchange.test_cold_wall_cools_warm_gas

(

self

)

Runs both ways. A LOX-cold line chills the gas put through it, which
is the chilldown of a downstream fitting rather than a special case.

Definition at line 96 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_gas_never_overshoots_the_wall()

None test_wall.TestExchange.test_gas_never_overshoots_the_wall

(

self

)

Effectiveness is bounded by one, so the stream can approach the metal
and never pass it, whatever the geometry.

Definition at line 105 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_heat_agrees_with_the_temperature_rise()

None test_wall.TestExchange.test_heat_agrees_with_the_temperature_rise

(

self

)

Q = mdot.cp.dT, or the wall's book-keeping does not close.

Definition at line 137 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_laminar_uses_a_fixed_nusselt()

None test_wall.TestExchange.test_laminar_uses_a_fixed_nusselt

(

self

)

Below the laminar limit Dittus-Boelter does not apply. It is not merely
inaccurate there -- it tends to zero with flow, so a trickle would come
out predicting no heat transfer at all, when the real answer is the
fully-developed laminar value.

Definition at line 158 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_missing_property_is_not_a_crash()

None test_wall.TestExchange.test_missing_property_is_not_a_crash	(		self,
		str	bad )

A property gap must cost the line its heat, not the tick its life.

Definition at line 172 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_more_flow_means_less_warming_per_kilogram()

None test_wall.TestExchange.test_more_flow_means_less_warming_per_kilogram

(

self

)

NTU falls as mdot rises: a faster stream has less residence time, so
each kilogram picks up less even though the total heat goes up.

Definition at line 115 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_more_metal_area_means_more_pickup()

None test_wall.TestExchange.test_more_metal_area_means_more_pickup

(

self

)

Definition at line 128 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_no_flow_no_heat()

None test_wall.TestExchange.test_no_flow_no_heat

(

self

)

The single most important guard in this file.

With no flow there is no convection, and a wall that leaked heat into a
stationary node would warm a stand that is just sitting there -- which
is the soak model this deliberately does not have, arriving by the back
door and wrong.

Definition at line 75 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_reverse_flow_is_treated_by_magnitude()

None test_wall.TestExchange.test_reverse_flow_is_treated_by_magnitude

(

self

)

A negative mdot is the solver's sign convention, not a different
physical situation; the line still picks up heat from its metal.

Definition at line 146 of file test_wall.py.

References test_wall.a_line(), and exchange().

test_warm_wall_warms_cold_gas()

None test_wall.TestExchange.test_warm_wall_warms_cold_gas

(

self

)

Definition at line 89 of file test_wall.py.

References test_wall.a_line(), and exchange().

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The documentation for this class was generated from the following file:

• lib/feedtwin/tests/test_wall.py