Regarding Coefficient-of-Discharge of intake port
 

Hi,

In STAR-CD how to find Coefficient Of Dischage(Cd) of intake port/manifold.Actually i did steady flow analysis for induction stroke now i want to find out Cd for inlet manifold ....kindly guide me how to get Cd.

With Regrds.

LeelaPrasd.

Re: Regarding Coefficient-of-Discharge of intake p
 

hi

you can find what you need at http://www.adapco-online.com/adapco_...frontpage.html

anyway it follows a copy of what you requested. bye

michele

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(5) Calculation of Discharge and Swirl Coefficients: ! !-Calculation of Discharge Coefficient (CD): ! *CLEAR *SET MASS 0.085 $!-Inlet Mass Flow Rate (kg/s) *SET DVAL 0.04683 $!-Valve Diameter (m) *SET GAMMA 1.4 $!-Ratio of specific heats *SET LIFT 0.01225 $!-Valve Lift (m) *SET M 28.96 $!-Molecular weight (kg/kmol) *SET REG1 1 $!-Inlet boundary region number *SET REG2 2 $!-Outlet boundary region number *SET SCAL 0.001 $!-Geometry Scale Factor ! ! CD = MA / MTH ! MA = Actual Mass Flow Rate ! MTH = Theoretical Mass Flow Rate ! = AREF * PTOT * SQRT [ A1 * A2 * A3 ] ! ! AREF = 2 * PI * DVAL * LIFT (= Reference Area (m**2)) ! ! A1 = 2 * GAMMA / ( (GAMMA-1) * R * TTOT ) ! ! A2 = (P/PTOT)**(2/GAMMA) ! ! A3 = 1 - (P/PTOT)**((GAMMA - 1)/ GAMMA) ! ! P = Outlet Static Pressure ! ! PTOT = Plenum inlet total pressure ! ! TTOT = Plenum inlet total temperature ! ! R = gas constant ! *SET,MA,MASS *SET,PI,3.14159 *SET,AREF,2.0 * PI * DVAL * LIFT *SET,R,8314.4 / M CSET,NEWS,FLUID ! !-Get Cell Data: ! LOAD,, OPER,CLEAR,1,6 OPER,GETC,PSTA,1,ABSO OPER,GETC,PTOT,2,ABSO OPER,GETC,TTOT,3,ABSO OPER,GETC,VOLU,4 OPER,SMULT,SCALE * SCALE * SCALE 4 4 ! ! Step 1 - Calculate Quantities at Outlet: ! BSET,NEWS,REGI,REG2 VSET,NEWS,BSET CSET,NEWS,VSET,ANY CSET,SUBS,FLUID ! ! Calculate Volume Averaged Static Pressure P: ! OPER,MULT,1,4,6 *GET,VOLU,RTOT,4 *GET,P,RTOT,6 *SET,P,P / VOLU ! ! Step 2 - Calculate Quantities at Inlet: ! BSET,NEWS,REGI,REG1 VSET,NEWS,BSET CSET,NEWS,VSET,ANY CSET,SUBS,FLUID ! ! Calculate Volume Averaged Total Pressure PTOT: ! OPER,MULT,2,4,6 *GET,VOLU,RTOT,4 *GET,PTOT,RTOT,6 *SET,PTOT,PTOT / VOLU ! ! Calculate Volume Averaged Total Temperature TTOT: ! OPER,MULT,3,4,6 *GET,VOLU,RTOT,4 *GET,TTOT,RTOT,6 *SET,TTOT,TTOT / VOLU ! ! Step 3 - Calculate Coefficient: ! *SET,A1,GAMMA - 1 * R * TTOT *SET,A1,2 * GAMMA / A1 *SET,A2,2 / GAMMA *SET,A2,P / PTOT ** A2 *SET,A3,GAMMA - 1 / GAMMA *SET,A3,P / PTOT ** A3 *SET,A3,1 - A3 *CALC,MTH,AREF * PTOT,SQRT,A1 * A2 * A3 *SET,CD,MA / MTH *LIST,CD

! !-Calculation of Impulse Meter Swirl Coefficient (CS): ! *CLEAR *SET,BORE,0.0934056 $!-Bore Diameter *SET,CSYS,78 $!-Cylindrical Coordinate System for Cylinder *SET,GAMMA,1.4 $!-Ratio of specific heats *SET,MASS,0.085 $!-Mass flow rate *SET,REG1,1 $!-Inlet Boundary Region Number *SET,SCALE,0.001 $!-Geometry Scale Factor *SET,M,28.96 $!-Molecular weight (kg/kmol) SPOINT,0,-92,0 $!-Section location (PROSTAR units) SNORM,0,1,0 LOCAL,78,CYLI,0,0,0,0,-90,0 ! ! CS = 8 * T / MA / VREF / B ! ! Where: ! ! T = SUM [R * VW * DENS * VA * AN] = Torque ! ! SUM = Summation over all cells at section location ! R = Radius of centroid of cell I ! VW = Tangential velocity in cell I ! DENS = Density in cell I ! AN = Area of cell normal to cylinder axis (m^2) ! VA = Axial velocity through cell I ! MA = Mass flow rate through port (kg/s) ! B = Cylinder bore diameter (m) ! VREF = Reference velocity (m/s) ! = SQRT [ A1 * A2 * A3 ] ! ! A1 = 2 * GAMMA / (GAMMA - 1) ! A2 = R * TTOT ! A3 = 1 - (P/PTOT)**((GAMMA - 1)/ GAMMA) ! ! PTOT = Plenum inlet total pressure ! P = Static pressure at section location ! TTOT = Plenum inlet total temperature ! R = Gas constant ! *SET,PI,3.14159 *SET,B,BORE *SET,MA,MASS *SET,R,8314.4 / M LOAD,, CSET,NEWS,FLUID OPER,CLEAR,ALL ! ! Step 1 - Determine Torque T ! ! Put radial distance in register 5: ! OPER,GETC,X,CSYS,5 OPER,SMUL,SCALE,5,5 ! ! Put tangential velocity sv (VW) and axial velocity sw (VA) ! in registers 2 and 6: ! PSYS,CSYS OPER,GETC,SV,2 OPER,GETC,SW,6 ! ! Make register 4 be the following product: R*VW*DENS*VA ! OPER,GETC,DENS,4 OPER,MULT,5,4,4 OPER,MULT,2,4,4 OPER,MULT,6,4,4 SUMM,CSET ! ! Put u,v,w in csys 1 in registers 1,2,3 respectively: ! PSYS,1 OPER,GETC,SU,1 OPER,GETC,SV,2 OPER,GETC,SW,3 SUMM,CSET OPER,PLLOAD SUMM,CSET ! ! Perform summation to calculate torque: ! INTEGRATE,CSET *GET,T,TAS ! ! Step 2 - Calculate Reference Velocity VREF: ! ! Calculate static pressure P at section location: ! GETC,ALL,P,ABSO INTE,CSET *GET,TAS,TAS *GET,TAREA,TAREA *SET,P,TAS / TAREA ! ! Calculate inlet total pressure PTOT: ! BSET,NEWS,REGI,REG1 VSET,NEWS,BSET CSET,NEWS,VSET,ANY CSET,SUBS,FLUID OPER,CLEAR,ALL OPER,GETC,PTOT,1,ABSO OPER,GETC,TTOT,3,ABSO OPER,GETC,VOLU,4 OPER,SMUL,SCALE * SCALE * SCALE,4,4 OPER,MULT,1,4,6 SUMM,CSET *GET,VOLU,RTOT,4 *GET,PTOT,RTOT,6 *SET,PTOT,PTOT / VOLU ! ! Calculate inlet total temperature TTOT: ! OPER,MULT,3,4,6 SUMM,CSET *GET,VOLU,RTOT,4 *GET,TTOT,RTOT,6 *SET,TTOT,TTOT / VOLU ! ! Calculate reference velocity VREF: ! *SET,A1,GAMMA - 1 *SET,A1,2 * GAMMA / A1 *SET,A2,R * TTOT *SET,A3,GAMMA - 1 / GAMMA *SET,A3,P / PTOT ** A3 *SET,A3,1 - A3 *CALC,VREF,1.0,SQRT,A1 * A2 * A3 ! ! Step 3 - Calculate Coefficient: ! *SET,CS,8 * T / MA / VREF / B *LIST,CS

Hi..the link is not working. It is hard to get details from above.cAN U PROVIDE ALTERNATIVE LINK.