I am trying to create a simple moist air model and getting an error which I am unable to understand. Please help if you understand this.

and am getting the following error

An error occurred while running the simulation and the simulation was terminated

Caused by:

• [' test / Solver Configuration2 ']: Initial conditions solve failed to converge.
• all components and nodal across variable Involved Can not solve for one or more variables, Including dynamic variable derivatives: Time derivative of 'x2_Port_Constant_Volume_Chamber_MA.T_I' (temperature of moist air volume) Time derivative of 'x2_Port_Constant_Volume_Chamber_MA.p_I' (pressure of moist air volume) 'Controlled_Reservoir_MA.Phi_A' (Mixture energy flow rate into port A) 'Controlled_Reservoir_MA.convection_A.Phi' (Mixture energy flow rate into the port) 'Controlled_Reservoir_MA.convection_A.mdot' (Mixture mass flow rate into the port) 'Controlled_Reservoir_MA.mdot_A ' (Mixture mass flow rate into port A)'x2_Port_Constant_Volume_Chamber_MA.convection_A.mdot' (Mixture mass flow rate into the port) 'x2_Port_Constant_Volume_Chamber_MA.mdot_A' (Mixture mass flowrate into port A) 'x2_Port_Constant_Volume_Chamber_MA.Phi_A' (Mixture energy flow rate into port A) 'x2_Port_Constant_Volume_Chamber_MA.convection_A.Phi ' (Mixture energy flow rate into the port) Equations of one or more components may be dependent or inconsistent. This can cause problems in transient initialization. Here is the set of components involved: all components involved 'test / 2-Port Constant Volume Chamber (MA)' Equation locations are:'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ two_port_constant_volume_chamber.ssc' (line 200) 'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ two_port_constant_volume_chamber.ssc ' (line 201) ' test / Controlled Reservoir (MA) ' Equation locations are: ' C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ controlled_reservoir.ssc ' (line 104) ' C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ controlled_reservoir.ssc ' (line 215) ' test / Reservoir (MA) ' Equation locations are:'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ reservoir.ssc' (line 193) 'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ reservoir.ssc ' (line 85) Problems possible for transient initialization, as well as stepsize control for transient solve, due to equations (including nonlinear equations) of one or more components: all components involved 'test / 2-Port Constant Volume Chamber (MA)' Equation locations are: 'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ two_port_constant_volume_chamber.ssc ' (line 210)'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ two_port_constant_volume_chamber.ssc' (line 200) 'test / Controlled Reservoir (MA)' Equation locations are : 'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ controlled_reservoir.ssc' (line 104) 'C: \ Program Files \ MATLAB \ R2018b \ toolbox \ physmod \ simscape \ library \ m \ + foundation \ + moist_air \ + elements \ controlled_reservoir.ssc (line 215)

[Gerrit Brandes]

Facing the same problem. Did you solve this somehow?

[Ze Chen]

switch off the 'Provide input signal for pressure' for the reservoir, use a pressure source instead

[Ze Chen]

Or you should add one local restriction at downstream of reservoir