| Author | Message | ||||
     Emin kebeli (dextermania) New member Username: dextermania Post Number: 2 Registered: 05-2009 |
we need to solve these equation can you help us please? | ||||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 1257 Registered: 06-2003 |
I think if you read through the User Guide and study some of the example problems, you should be able to see how to pose your problem. If you still have trouble, you can post your FlexPDE script with specific questions. PS The package of XML files you posted is not usable by any application we have in house. | ||||
| Emin kebeli (dextermania) Junior Member Username: dextermania Post Number: 3 Registered: 05-2009 |
I did some equtions with using some equalities but I didnt find some of equations cartesian equalities. I dont how to write boundry conditions on 3D. These equaiton are governing equations. founded equtions are; a) Conservation of Mass b) Conservation of u- momentum c) Conservation of v-momentum d) Conservation of w-momentum not founded equtions are; a) Conservation of energy(picture 1) b) the mass conservation of water vapor and contaminant gas ( picture 2) can you help the write these please? TITLE 'Governing Equations' { the problem identification } COORDINATES cartesian3 { coordinate system, 1D,2D,3D, etc } VARIABLES { system variables } u { velocity, m/s } p { pressure; partial pressure (with subscript), Pa} g {gravitational acceleration, m/s2} T {temperature; mean temperature (with subscript), C} Ww { concentration of water vapor} Wc { concentration of contaminant gas} DEFINITIONS { parameter definitions } q {density of air, kg/m3} m { viscosity of air, kg/(m s)} cp {specific heat of air, J/(kg K)} k {thermal conductivity of air, W/(m K)} b {thermal expansion coefficient, K 1} Dwa { mass diffusivity of water vapor in air} Dca { mass diffusivity of contaminant gas in air} Tref {reference temperature} INITIAL VALUES EQUATIONS { PDE's, one for each variable } (du/dx)+(dv/dy)+(dw/dz)=0 {the conservation of mass} q*((du/dt)+u*(du/dx)+v*(du/dy)+w*(du/dx))+(dq/dx)=0 {the conservation of u-Momentum Equation} q*((dv/dt)+u*(dv/dx)+v*(dv/dy)+w*(dv/dy))+(dq/dy)=0 {the conservation of v-Momentum Equation} q*((dw/dt)+u*(dw/dx)+v*(dw/dy)+w*(dw/dz))+(dq/dz)=0 {the conservation of w-Momentum Equation} | ||||
| Emin kebeli (dextermania) Member Username: dextermania Post Number: 4 Registered: 05-2009 |
| ||||
| Emin kebeli (dextermania) Member Username: dextermania Post Number: 5 Registered: 05-2009 |
hi I have problem for operating room condition and defined some vectoral equations but it didnt run which equations are wrong? can you help me please? { Fill in the following sections (removing comment marks ! if necessary), and delete those that are unused.} TITLE 'Operating Room' { the problem identification } COORDINATES cartesian2 { coordinate system, 1D,2D,3D, etc } VARIABLES { system variables } Ui, Uj {velocity components} xi, xj {rectilinear orthogonal coordinates} P { pressure} r {fluid density} v {molecular viscosity} vt {turbulent viscosity} B {Volumetric expansion coefficient } gi {gravitational constant in i direction } T {Temperature } K {Turbulent kinetic energy } e {Dissipation rate of k } C1, C2 {empirical constant in generation/destruction term of e equation } C3 {empirical constant in buoyant term of e equation } CD {empirical constant for eddy viscosity } kt {Thermal diffusivity } dp {particle diameter } rp {particle density } CDp {drag coefficient } Fi {additional acceleration (force/unit particle mass) term } qN {mean volumetric heat source generation rate (kW=m3)} Q {dependent variable} ! SELECT { method controls } ! DEFINITIONS { parameter definitions } INITIAL VALUES C1 = 1.44, C2 = 1.92, C3 = 0.0, CD = 0.09, k = 1.0, sk= 1.3, st = 0.9 , R = 2.98 × (10^-5), S = 0.0 EQUATIONS { PDE's, one for each variable } (dUi/dxi)=0 {Continuity} Uj*(dUi/dxj)=[(-1/r)*(dP/dxi)]+[(d/dxj)*((v+vt)*((dUj/dxi)+(dUi/dxj)))]-(B*gi*T) { Momentum} Uj*(dk/dxj)=(d/dxi)*[v+(vt/sk)*(dk/dxj)]+(vt*((dUj/dxi)+(dUi/dxj)))*(dUi/dxj)+[B *gi*(vt/st)*(dT/dxi)]-e { Turbulence kinetic energy} Ui*(dT/dxi)=(d/dxi)*[kt+(vt/st)]*(dT/dxi)+qN {Thermal energy} Uj*(de/dxj)=(d/dxi)*[v+(vt/sk)*(de/dxj)]+((e/k)*(C1*vt*(dUj/dxi)+(dUi/dxj)))*(dU i/dxj)-C2*((e*e)/k)+[C3*B*gi*(vt/st)*(dT/dxi)] {Dissipation rate of turbulence kinetic energy} vt=CD*((k*k)/e) { Eddy viscosity} (d/dt)*(r*Q)+div(r*((dUj/dxi)+(dUi/dxj))*Q-R*grad(Q))=S { Particulate transportation} ! CONSTRAINTS { Integral constraints } BOUNDARIES { The domain definition } REGION 1 { For each material region } START(0,0) { Walk the domain boundary } LINE TO (1,0) TO (1,1) TO (0,1) TO CLOSE ! TIME 0 TO 1 { if time dependent } MONITORS { show progress } PLOTS { save result displays } CONTOUR(u) END | ||||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 1264 Registered: 06-2003 |
Your posted script is thoroughly inconsistent with the principles of FlexPDE script preparation. I suggest you read the User Guide (in the online help) before proceding any farther. Then look at the sample problems in the "Samples | Applications | Fluids" folder. (This is a version 6 path. In version 5, look at "Samples | Steady_State | Fluids" and "Samples | Time_Dependent | Fluids"). This problem is probably beyond the capabilities of the free student version. |
need to solve