<!-- Airbus A320 APU --> <!-- Copyright (c) 2020 Jonathan Redpath --> <system name="A320: APU"> <channel name="APU" execrate="8"> <!-- bleed 1.8 kg / sec @ 42 psig --> <!-- fuel 148 kg/hr --> <!-- generator 24034 rpm, 10129 rpm fuel ctl, 32045 rpm starter, 51965 rpm cooling, 4137rpm oil pump --> <fcs_function name="/systems/apu/bleed-load-kw"> <function> <ifthen> <eq> <property>/controls/pneumatics/switches/apu</property> <value>1</value> </eq> <value>252</value> <value>0</value> </ifthen> </function> </fcs_function> <fcs_function name="/systems/apu/electrical-load-kw"> <function> <ifthen> <gt> <property>/systems/electrical/relay/apu-glc/output</property> <value>110</value> </gt> <value>132</value> <value>0</value> </ifthen> </function> </fcs_function> <fcs_function name="/systems/apu/apu-load-cmd"> <function> <quotient> <sum> <property>/systems/apu/electrical-load-kw</property> <property>/systems/apu/bleed-load-kw</property> </sum> <value>400</value> </quotient> </function> </fcs_function> <actuator name="/systems/apu/apu-load"> <input>/systems/apu/apu-load-cmd</input> <rate_limit>0.01</rate_limit> <!-- 60 seconds cooling period for bleed which is ~ 60% --> </actuator> <washout_filter name="/systems/apu/dn-dt"> <input>/engines/engine[2]/n1</input> <c1>1</c1> </washout_filter> <fcs_function name="/systems/apu/egt-degC"> <function> <sum> <product> <property>/systems/apu/apu-load</property> <value>50</value> </product> <ifthen> <or> <lt> <property>/engines/engine[2]/n1</property> <value>0.5</value> </lt> <gt> <property>/systems/apu/dn-dt</property> <value>0</value> </gt> </or> <table> <independentVar lookup="row">/engines/engine[2]/n1</independentVar> <tableData> 5.0 20.0 8.0 45.0 10.0 120.0 12.0 225.0 18.0 430.0 25.0 500.0 27.0 560.0 30.0 720.0 35.0 785.0 40.0 800.0 45.0 795.0 50.0 785.0 60.0 755.0 75.0 645.0 90.0 520.0 100.0 415.0 </tableData> </table> <table> <independentVar lookup="row">/engines/engine[2]/n1</independentVar> <tableData> 2.0 200.0 8.0 220.0 12.0 225.0 18.0 240.0 30.0 250.0 50.0 265.0 60.0 295.0 75.0 380.0 90.0 410.0 100.0 415.0 </tableData> </table> </ifthen> </sum> </function> </fcs_function> <fcs_function name="/systems/apu/oil/oil-pressure-psi"> <function> <table> <independentVar lookup="row">/engines/engine[2]/n1</independentVar> <independentVar lookup="column">/systems/apu/oil/level-l</independentVar> <tableData> 0 3.6 5.4 8 0 0 0 12 0 1 10 18 0 5 22 30 0 22 41 50 0 25 45 60 0 28 48 75 0 33 52 90 0 35 54 100 0 36 55 </tableData> </table> </function> </fcs_function> <fcs_function name="/systems/apu/oil/oil-temperature-degC"> <function> <product> <sum> <value>1.0</value> <!-- tune --> <product> <property>/systems/apu/apu-load</property> <value>0.3</value> </product> </sum> <table> <independentVar lookup="row">/systems/apu/oil/oil-pressure-psi</independentVar> <tableData> 0 0 25 135 35 105 55 85 </tableData> </table> <quotient> <property>/engines/engine[2]/n1</property> <value>100</value> </quotient> </product> </function> </fcs_function> <fcs_function name="/systems/apu/oil/calc-oil-level"> <function> <sum> <property>/systems/apu/oil/level-l</property> <product> <quotient> <property>/engines/engine[2]/n1</property> <value>100</value> </quotient> <property>/systems/apu/oil/allow-oil-consumption</property> <value>-0.00000131437</value> <property>simulation/channel-dt</property> </product> </sum> </function> <output>/systems/apu/oil/level-l</output> </fcs_function> <switch name="/systems/apu/shutdown-power-loss-cmd"> <default value="0"/> <test logic="AND" value="1"> /systems/electrical/bus/dc-bat lt 25 </test> </switch> <actuator name="/systems/apu/shutdown-power-loss-timer"> <input>/systems/apu/shutdown-power-loss-cmd</input> <rate_limit sense="incr">5</rate_limit> <rate_limit sense="decr">100</rate_limit> </actuator> <switch name="/systems/apu/shutdown-power-loss"> <default value="0"/> <test logic="AND" value="1"> /systems/apu/shutdown-power-loss-timer eq 1 </test> </switch> </channel> </system>