mass flow in is not equal to mass flow out

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 September 17, 2009, 09:08 mass flow in is not equal to mass flow out #1 New Member   anonymous Join Date: Sep 2009 Posts: 2 Rep Power: 0 Can anyone pls help me with this problem. My problem is mass flow in is not equal to mass flow out. thank you This is my model This is my CCL infor: # State file created: 2009/09/14 15:18:14 # CFX-12.0.1 build 2009.04.14-23.02 LIBRARY: CEL: EXPRESSIONS: DenH = (DenWater - DenRef) DenRef = 1.185 [kg m^-3] DenWater = 997 [kg m^-3] DownH = 0.68 [m] DownPres = DenH*g*DownVFWater*(DownH-y) DownVFAir = step((y-DownH)/1[m]) DownVFWater = 1-DownVFAir UpH = 0.78 [m] UpPres = DenH*g*UpVFWater*(UpH-y) UpVFAir = step((y-UpH)/1[m]) UpVFWater = 1-UpVFAir END END MATERIAL GROUP: Air Data Group Description = Ideal gas and constant property air. Constant \ properties are for dry air at STP (0 C, 1 atm) and 25 C, 1 atm. END MATERIAL GROUP: CHT Solids Group Description = Pure solid substances that can be used for conjugate \ heat transfer. END MATERIAL GROUP: Calorically Perfect Ideal Gases Group Description = Ideal gases with constant specific heat capacity. \ Specific heat is evaluated at STP. END MATERIAL GROUP: Constant Property Gases Group Description = Gaseous substances with constant properties. \ Properties are calculated at STP (0C and 1 atm). Can be combined with \ NASA SP-273 materials for combustion modelling. END MATERIAL GROUP: Constant Property Liquids Group Description = Liquid substances with constant properties. END MATERIAL GROUP: Dry Peng Robinson Group Description = Materials with properties specified using the built \ in Peng Robinson equation of state. Suitable for dry real gas modelling. END MATERIAL GROUP: Dry Redlich Kwong Group Description = Materials with properties specified using the built \ in Redlich Kwong equation of state. Suitable for dry real gas modelling. END MATERIAL GROUP: Dry Steam Group Description = Materials with properties specified using the IAPWS \ equation of state. Suitable for dry steam modelling. END MATERIAL GROUP: Gas Phase Combustion Group Description = Ideal gas materials which can be use for gas phase \ combustion. Ideal gas specific heat coefficients are specified using \ the NASA SP-273 format. END MATERIAL GROUP: IAPWS IF97 Group Description = Liquid, vapour and binary mixture materials which use \ the IAPWS IF-97 equation of state. Materials are suitable for \ compressible liquids, phase change calculations and dry steam flows. END MATERIAL GROUP: Interphase Mass Transfer Group Description = Materials with reference properties suitable for \ performing either Eulerian or Lagrangian multiphase mass transfer \ problems. Examples include cavitation, evaporation or condensation. END MATERIAL GROUP: Liquid Phase Combustion Group Description = Liquid and homogenous binary mixture materials which \ can be included with Gas Phase Combustion materials if combustion \ modelling also requires phase change (eg: evaporation) for certain \ components. END MATERIAL GROUP: Particle Solids Group Description = Pure solid substances that can be used for particle \ tracking END MATERIAL GROUP: Peng Robinson Dry Hydrocarbons Group Description = Common hydrocarbons which use the Peng Robinson \ equation of state. Suitable for dry real gas models. END MATERIAL GROUP: Peng Robinson Dry Refrigerants Group Description = Common refrigerants which use the Peng Robinson \ equation of state. Suitable for dry real gas models. END MATERIAL GROUP: Peng Robinson Dry Steam Group Description = Water materials which use the Peng Robinson equation \ of state. Suitable for dry steam modelling. END MATERIAL GROUP: Peng Robinson Wet Hydrocarbons Group Description = Common hydrocarbons which use the Peng Robinson \ equation of state. Suitable for condensing real gas models. END MATERIAL GROUP: Peng Robinson Wet Refrigerants Group Description = Common refrigerants which use the Peng Robinson \ equation of state. Suitable for condensing real gas models. END MATERIAL GROUP: Peng Robinson Wet Steam Group Description = Water materials which use the Peng Robinson equation \ of state. Suitable for condensing steam modelling. END MATERIAL GROUP: Real Gas Combustion Group Description = Real gas materials which can be use for gas phase \ combustion. Ideal gas specific heat coefficients are specified using \ the NASA SP-273 format. END MATERIAL GROUP: Redlich Kwong Dry Hydrocarbons Group Description = Common hydrocarbons which use the Redlich Kwong \ equation of state. Suitable for dry real gas models. END MATERIAL GROUP: Redlich Kwong Dry Refrigerants Group Description = Common refrigerants which use the Redlich Kwong \ equation of state. Suitable for dry real gas models. END MATERIAL GROUP: Redlich Kwong Dry Steam Group Description = Water materials which use the Redlich Kwong equation \ of state. Suitable for dry steam modelling. END MATERIAL GROUP: Redlich Kwong Wet Hydrocarbons Group Description = Common hydrocarbons which use the Redlich Kwong \ equation of state. Suitable for condensing real gas models. END MATERIAL GROUP: Redlich Kwong Wet Refrigerants Group Description = Common refrigerants which use the Redlich Kwong \ equation of state. Suitable for condensing real gas models. END MATERIAL GROUP: Redlich Kwong Wet Steam Group Description = Water materials which use the Redlich Kwong equation \ of state. Suitable for condensing steam modelling. END MATERIAL GROUP: Soot Group Description = Solid substances that can be used when performing \ soot modelling END MATERIAL GROUP: User Group Description = Materials that are defined by the user END MATERIAL GROUP: Water Data Group Description = Liquid and vapour water materials with constant \ properties. Can be combined with NASA SP-273 materials for combustion \ modelling. END MATERIAL GROUP: Wet Peng Robinson Group Description = Materials with properties specified using the built \ in Peng Robinson equation of state. Suitable for wet real gas modelling. END MATERIAL GROUP: Wet Redlich Kwong Group Description = Materials with properties specified using the built \ in Redlich Kwong equation of state. Suitable for wet real gas modelling. END MATERIAL GROUP: Wet Steam Group Description = Materials with properties specified using the IAPWS \ equation of state. Suitable for wet steam modelling. END MATERIAL: Air Ideal Gas Material Description = Air Ideal Gas (constant Cp) Material Group = Air Data, Calorically Perfect Ideal Gases Option = Pure Substance Thermodynamic State = Gas PROPERTIES: Option = General Material EQUATION OF STATE: Molar Mass = 28.96 [kg kmol^-1] Option = Ideal Gas END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 1.0044E+03 [J kg^-1 K^-1] Specific Heat Type = Constant Pressure END REFERENCE STATE: Option = Specified Point Reference Pressure = 1 [atm] Reference Specific Enthalpy = 0. [J/kg] Reference Specific Entropy = 0. [J/kg/K] Reference Temperature = 25 [C] END DYNAMIC VISCOSITY: Dynamic Viscosity = 1.831E-05 [kg m^-1 s^-1] Option = Value END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 2.61E-2 [W m^-1 K^-1] END ABSORPTION COEFFICIENT: Absorption Coefficient = 0.01 [m^-1] Option = Value END SCATTERING COEFFICIENT: Option = Value Scattering Coefficient = 0.0 [m^-1] END REFRACTIVE INDEX: Option = Value Refractive Index = 1.0 [m m^-1] END END END MATERIAL: Air at 25 C Material Description = Air at 25 C and 1 atm (dry) Material Group = Air Data, Constant Property Gases Option = Pure Substance Thermodynamic State = Gas PROPERTIES: Option = General Material EQUATION OF STATE: Density = 1.185 [kg m^-3] Molar Mass = 28.96 [kg kmol^-1] Option = Value END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 1.0044E+03 [J kg^-1 K^-1] Specific Heat Type = Constant Pressure END REFERENCE STATE: Option = Specified Point Reference Pressure = 1 [atm] Reference Specific Enthalpy = 0. [J/kg] Reference Specific Entropy = 0. [J/kg/K] Reference Temperature = 25 [C] END DYNAMIC VISCOSITY: Dynamic Viscosity = 1.831E-05 [kg m^-1 s^-1] Option = Value END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 2.61E-02 [W m^-1 K^-1] END ABSORPTION COEFFICIENT: Absorption Coefficient = 0.01 [m^-1] Option = Value END SCATTERING COEFFICIENT: Option = Value Scattering Coefficient = 0.0 [m^-1] END REFRACTIVE INDEX: Option = Value Refractive Index = 1.0 [m m^-1] END THERMAL EXPANSIVITY: Option = Value Thermal Expansivity = 0.003356 [K^-1] END END END MATERIAL: Aluminium Material Group = CHT Solids, Particle Solids Option = Pure Substance Thermodynamic State = Solid PROPERTIES: Option = General Material EQUATION OF STATE: Density = 2702 [kg m^-3] Molar Mass = 26.98 [kg kmol^-1] Option = Value END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 9.03E+02 [J kg^-1 K^-1] END REFERENCE STATE: Option = Specified Point Reference Specific Enthalpy = 0 [J/kg] Reference Specific Entropy = 0 [J/kg/K] Reference Temperature = 25 [C] END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 237 [W m^-1 K^-1] END END END MATERIAL: Copper Material Group = CHT Solids, Particle Solids Option = Pure Substance Thermodynamic State = Solid PROPERTIES: Option = General Material EQUATION OF STATE: Density = 8933 [kg m^-3] Molar Mass = 63.55 [kg kmol^-1] Option = Value END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 3.85E+02 [J kg^-1 K^-1] END REFERENCE STATE: Option = Specified Point Reference Specific Enthalpy = 0 [J/kg] Reference Specific Entropy = 0 [J/kg/K] Reference Temperature = 25 [C] END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 401.0 [W m^-1 K^-1] END END END MATERIAL: Soot Material Group = Soot Option = Pure Substance Thermodynamic State = Solid PROPERTIES: Option = General Material EQUATION OF STATE: Density = 2000 [kg m^-3] Molar Mass = 12 [kg kmol^-1] Option = Value END REFERENCE STATE: Option = Automatic END ABSORPTION COEFFICIENT: Absorption Coefficient = 0 [m^-1] Option = Value END END END MATERIAL: Steel Material Group = CHT Solids, Particle Solids Option = Pure Substance Thermodynamic State = Solid PROPERTIES: Option = General Material EQUATION OF STATE: Density = 7854 [kg m^-3] Molar Mass = 55.85 [kg kmol^-1] Option = Value END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 4.34E+02 [J kg^-1 K^-1] END REFERENCE STATE: Option = Specified Point Reference Specific Enthalpy = 0 [J/kg] Reference Specific Entropy = 0 [J/kg/K] Reference Temperature = 25 [C] END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 60.5 [W m^-1 K^-1] END END END MATERIAL: Water Material Description = Water (liquid) Material Group = Water Data, Constant Property Liquids Option = Pure Substance Thermodynamic State = Liquid PROPERTIES: Option = General Material EQUATION OF STATE: Density = 997.0 [kg m^-3] Molar Mass = 18.02 [kg kmol^-1] Option = Value END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 4181.7 [J kg^-1 K^-1] Specific Heat Type = Constant Pressure END REFERENCE STATE: Option = Specified Point Reference Pressure = 1 [atm] Reference Specific Enthalpy = 0.0 [J/kg] Reference Specific Entropy = 0.0 [J/kg/K] Reference Temperature = 25 [C] END DYNAMIC VISCOSITY: Dynamic Viscosity = 8.899E-4 [kg m^-1 s^-1] Option = Value END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 0.6069 [W m^-1 K^-1] END ABSORPTION COEFFICIENT: Absorption Coefficient = 1.0 [m^-1] Option = Value END SCATTERING COEFFICIENT: Option = Value Scattering Coefficient = 0.0 [m^-1] END REFRACTIVE INDEX: Option = Value Refractive Index = 1.0 [m m^-1] END THERMAL EXPANSIVITY: Option = Value Thermal Expansivity = 2.57E-04 [K^-1] END END END MATERIAL: Water Ideal Gas Material Description = Water Vapour Ideal Gas (100 C and 1 atm) Material Group = Calorically Perfect Ideal Gases, Water Data Option = Pure Substance Thermodynamic State = Gas PROPERTIES: Option = General Material EQUATION OF STATE: Molar Mass = 18.02 [kg kmol^-1] Option = Ideal Gas END SPECIFIC HEAT CAPACITY: Option = Value Specific Heat Capacity = 2080.1 [J kg^-1 K^-1] Specific Heat Type = Constant Pressure END REFERENCE STATE: Option = Specified Point Reference Pressure = 1.014 [bar] Reference Specific Enthalpy = 0. [J/kg] Reference Specific Entropy = 0. [J/kg/K] Reference Temperature = 100 [C] END DYNAMIC VISCOSITY: Dynamic Viscosity = 9.4E-06 [kg m^-1 s^-1] Option = Value END THERMAL CONDUCTIVITY: Option = Value Thermal Conductivity = 193E-04 [W m^-1 K^-1] END ABSORPTION COEFFICIENT: Absorption Coefficient = 1.0 [m^-1] Option = Value END SCATTERING COEFFICIENT: Option = Value Scattering Coefficient = 0.0 [m^-1] END REFRACTIVE INDEX: Option = Value Refractive Index = 1.0 [m m^-1] END END END END FLOW: Flow Analysis 1 SOLUTION UNITS: Angle Units = [rad] Length Units = [m] Mass Units = [kg] Solid Angle Units = [sr] Temperature Units = [K] Time Units = [s] END ANALYSIS TYPE: Option = Steady State EXTERNAL SOLVER COUPLING: Option = None END END DOMAIN: Domain 1 Coord Frame = Coord 0 Domain Type = Fluid Location = Assembly BOUNDARY: Boundary 1 Boundary Type = INLET Location = F98.104 BOUNDARY CONDITIONS: FLOW DIRECTION: Option = Normal to Boundary Condition END FLOW REGIME: Option = Subsonic END MASS AND MOMENTUM: Mass Flow Rate = 3 [kg s^-1] Option = Bulk Mass Flow Rate END END FLUID: air BOUNDARY CONDITIONS: VOLUME FRACTION: Option = Value Volume Fraction = UpVFAir END END END FLUID: water BOUNDARY CONDITIONS: VOLUME FRACTION: Option = Value Volume Fraction = UpVFWater END END END END BOUNDARY: Boundary 2 Boundary Type = OPENING Location = F100.104 BOUNDARY CONDITIONS: FLOW DIRECTION: Option = Normal to Boundary Condition END FLOW REGIME: Option = Subsonic END MASS AND MOMENTUM: Option = Opening Pressure and Direction Relative Pressure = DownPres END END FLUID: air BOUNDARY CONDITIONS: VOLUME FRACTION: Option = Value Volume Fraction = 0 END END END FLUID: water BOUNDARY CONDITIONS: VOLUME FRACTION: Option = Value Volume Fraction = 1 END END END END BOUNDARY: Boundary 3 Boundary Type = OPENING Location = F105.104,F108.104 BOUNDARY CONDITIONS: FLOW DIRECTION: Option = Normal to Boundary Condition END FLOW REGIME: Option = Subsonic END MASS AND MOMENTUM: Option = Opening Pressure and Direction Relative Pressure = DownPres END END FLUID: air BOUNDARY CONDITIONS: VOLUME FRACTION: Option = Value Volume Fraction = 1 END END END FLUID: water BOUNDARY CONDITIONS: VOLUME FRACTION: Option = Value Volume Fraction = 0 END END END END BOUNDARY: Domain 1 Default Boundary Type = WALL Location = \ F101.104,F102.104,F103.104,F106.104,F107.104,F109. 104,F110.104,F111.10\ 4,F112.104,F113.104,F114.104,F83.104,F84.104,F85.1 04,F86.104,F87.104,F\ 88.104,F89.104,F90.104,F91.104,F92.104,F93.104,F94 .104,F95.104,F96.104\ ,F97.104,F99.104 BOUNDARY CONDITIONS: MASS AND MOMENTUM: Option = No Slip Wall END END END DOMAIN MODELS: BUOYANCY MODEL: Buoyancy Reference Density = 1.185 [kg m^-3] Gravity X Component = 0 [m s^-2] Gravity Y Component = -9.8 [m s^-2] Gravity Z Component = 0 [m s^-2] Option = Buoyant BUOYANCY REFERENCE LOCATION: Option = Automatic END END DOMAIN MOTION: Option = Stationary END MESH DEFORMATION: Option = None END REFERENCE PRESSURE: Reference Pressure = 1 [atm] END END FLUID DEFINITION: air Material = Air at 25 C Option = Material Library MORPHOLOGY: Option = Continuous Fluid END END FLUID DEFINITION: water Material = Water Option = Material Library MORPHOLOGY: Option = Continuous Fluid END END FLUID MODELS: COMBUSTION MODEL: Option = None END FLUID: air FLUID BUOYANCY MODEL: Option = Density Difference END END FLUID: water FLUID BUOYANCY MODEL: Option = Density Difference END END HEAT TRANSFER MODEL: Fluid Temperature = 25 [C] Homogeneous Model = Off Option = Isothermal END THERMAL RADIATION MODEL: Option = None END TURBULENCE MODEL: Option = Laminar END END FLUID PAIR: air | water INTERPHASE TRANSFER MODEL: Option = None END MASS TRANSFER: Option = None END SURFACE TENSION MODEL: Option = None END END INITIALISATION: Option = Automatic FLUID: air INITIAL CONDITIONS: VOLUME FRACTION: Option = Automatic with Value Volume Fraction = UpVFAir END END END FLUID: water INITIAL CONDITIONS: VOLUME FRACTION: Option = Automatic with Value Volume Fraction = UpVFWater END END END INITIAL CONDITIONS: Velocity Type = Cartesian CARTESIAN VELOCITY COMPONENTS: Option = Automatic with Value U = 0 [m s^-1] V = 0 [m s^-1] W = 0 [m s^-1] END STATIC PRESSURE: Option = Automatic with Value Relative Pressure = 0 [Pa] END END END MULTIPHASE MODELS: Homogeneous Model = On FREE SURFACE MODEL: Option = Standard END END END MESH ADAPTION: Activate Adaption = On Domain Name = Domain 1 Save Intermediate Files = On Subdomain List = Assembly ADAPTION ADVANCED OPTIONS: Node Allocation Parameter = -2 Number of Adaption Levels = 2 END ADAPTION CONVERGENCE CRITERIA: Adaption Target Residual = 0.001 Maximum Iterations per Step = 100 Option = RMS Norm for Residuals END ADAPTION CRITERIA: Maximum Number of Adaption Steps = 2 Node Factor = 4 Option = Multiple of Initial Mesh Variables List = air.Conservative Volume Fraction END ADAPTION METHOD: Minimum Edge Length = 0.0 Option = Solution Variation END END OUTPUT CONTROL: RESULTS: File Compression Level = Default Option = Standard END END SOLVER CONTROL: ADVECTION SCHEME: Option = High Resolution END CONVERGENCE CONTROL: Length Scale Option = Conservative Maximum Number of Iterations = 100 Minimum Number of Iterations = 1 Timescale Control = Auto Timescale Timescale Factor = 1.0 END CONVERGENCE CRITERIA: Residual Target = 1.E-4 Residual Type = RMS END DYNAMIC MODEL CONTROL: Global Dynamic Model Control = Yes END END END COMMAND FILE: Version = 12.0.1 END

 September 18, 2009, 07:22 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 10,803 Rep Power: 85 Your simulation is not converged. Have you looked here: http://www.cfd-online.com/Wiki/Ansys...gence_criteria Also output some backup files as the simulation progresses. You can load them in CFD-Post and it may help you diagnose what is wrong.

 September 18, 2009, 08:07 #3 New Member   anonymous Join Date: Sep 2009 Posts: 2 Rep Power: 0 thank you. which tutorial should i look through, if i want to add lio into the flow?

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