Description: Creates an animation output file.
Format: ANIMATE KODE
Example: ANIMATE 1
Variable Description
KODE Code specifying the animated output
1 - Ring motion and inter-ring gas pressures
2 - Piston dynamics and combustion pressure
Notes:
1) The animation data files are created by the analysis programs. The ANIMATE program must be used to obtain the animated output.
2) If KODE = 1, a maximum of three rings may be animated.
3) Animation files have the extension .Axx, i.e., username.Axx.
Description: Identifies the file containing cylinder temperature data.
Format: BTEMP FILE
Example: BTEMP BTEMP.DAT
Variable Description
FILE Name of the data file that contains cylinder bore temperature data.
Notes:
1) If a BTEMP input data line is not included in the input data file, the cylinder bore is assumed to be at ambient temperature.
2) The format for data contained in this file is described in Appendix E of this user's manual.
3) Only one BTEMP input data line is allowed.
Input Data Line: C (or C****** or blank spaces)
Description: Defines a comment input data line.
Format: C COMMENT
Example: C THIS LINE IS A COMMENT
Example: C****** THIS LINE IS A COMMENT
Example: THIS LINE IS A COMMENT
Variable Description
COMMENT Alphanumeric comment (249 characters maximum).
Notes:
1) Any number of comment data lines may appear in the input data file.
Description: Defines the connecting rod geometry and mass.
Format: CONROD RODLEN RODCG MROD RODICG
Example: CONROD 7.50 3.00 1.02 0.034
| Variable | Description | Units |
|---|---|---|
| RODLEN | Length of connecting rod. | LENGTH |
| RODCG | Distance from center of crank pin to C.G. of connecting rod. | LENGTH |
| MROD | Mass of connecting rod. | MASS |
| RODICG | Mass moments of connecting rod about rod C.G. | MMOI |
Notes:
1) Only one CONROD input data line is allowed.
Connecting Rod
Description: Defines several program control parameters.
Format: CONTROL INCGP KSTOP KINCR KFAST
Example: CONTROL 5 1 10
| Variable | Description | Units | |
|---|---|---|---|
| INCGP | Number of increments per crank angle for gas flow calculations. | none | |
| KSTOP | Code to stop RING program after groove and inter-ring pressures and ring forces are calculated. | none | |
| none | 0 - Run entire program (default). | none | |
| none | 1 - Stop after pressure calculations. | none | |
| KINCR | Crank angle increment for film thickness and friction calculations. | ANGLE | |
| KFAST | Code to perform an axisymmetric ring film thickness and friction analysis: | none | |
| none | 0 - Asymmetric analysis (default). | none | |
| none | 1 - Axisymmetric analysis. | none | |
| none | 2 - Axisymmetric analysis with lubricant starvation. | none |
Notes:
1) This is not a required data line. If it is omitted, the default value for INCGP is 1, the default value for KSTOP is 0, the default value for KINCR is 10, and the default value for KFAST is 0.
2) The crank angle increment (KINCR) must be between 1 and 90.
3) An axisymmetric analysis (KFAST = 1) does not consider:
4) Only one CONTROL input data line is allowed.
a) Bore distortions,
b) Ring thermal gradients,
c) Ring twist, and
d) Ring cam shape pressure distribution.
Description: Defines bore diameter, piston stroke, crank offset and piston location at top-dead-center.
Format: CYLBORE BORE STROKE XCRANK PLOC
Example: CYLBORE 3.80 3.8 -0.001
| Variable | Description | Units |
|---|---|---|
| BORE | Nominal bore diameter. | LENGTH |
| STROKE | Piston stroke. | LENGTH |
| XCRANK | Offset of crank from bore centerline. Positive is to the right toward the antithrust side. | LENGTH |
| PLOC | Distance from top of deck to top of piston when piston is in top-dead-center (TDC) position. | LENGTH |
Notes:
1) Only one CYLBORE data line is allowed.
Cylinder Bore
Description: Defines parameters for ring/groove damping forces due to squeeze film and adhesion.
Format: DAMPF RID SFP ADP
Example: DAMPF 2 0.1 0.2
Variable Description
RID Ring identification number (1 RID4):
1 = Top compression ring.
2 = Second compression ring.
3 = Third compression ring.
4 = Oil control ring.
SFP Reduction parameter (fs) for squeeze film force (0 fs 1).
ADP Reduction parameter (fa) for adhesive force (0 fa 1).
Notes:
1) If a DAMPF input data line is not included in the input data file, the ring damping forces are set equal to zero.
2) The ring squeeze damping force (S) is given by
S = fshA(Rp-Rr)2/h3
where fs = Reduction parameter for squeeze film force
= Lub viscosity.
h = Relative velocity of ring with respect to groove.
A = Wetted area (same as for Q)
h = Distance between ring and groove.
3) The adhesive damping force (Q) is given by
Q = faPatmA
where fa = Reduction parameter for adhesive force.
Patm = Atmospheric pressure.
A = Wetted area between ring and groove =(R2p-R2r).
Damping Force
Description: Defines the analysis date.
Format: DATE DATEOFRUN
Example: DATE 12/05/94
Variable Description
DATEOFRUN Month/Day/Year
Notes: 1) The default date is blank.
2) Only one DATE input data line is allowed.
Description: Defines the orifice discharge coefficient.
Format: DCOEFF ODC Example: DCOEFF 0.86
Variable Description
ODC Orifice discharge coefficient. Notes:
1) If a DCOEFF input data line is not included in the input data file, the orifice discharge coefficient will be 0.65 for each ring in the ring pack. The orifice discharge coefficient specified on this data line is also used for the oil ring groove orifice area if one exists.
2) Only one DCOEFF input data line is allowed.
Description: Identifies the file containing mechanical bore distortion data.
Format: DISTORT FILE
Example: DISTORT MDIST.DAT
Variable Description
FILE Name of the data file that contains mechanical bore distortion data.
Notes:
1) If a DISTORT input data line is not included in the input data file, mechanical bore distortions will not be considered in the analysis.
2) Only one DISTORT input data line is allowed.
3) Mechanical bore distortions are defined in the data file identified on this input data line. These distortions are caused by machining tolerances and engine assembly (bolting of heads and manifolds). Thermal bore distortions are defined in a file identified on the THERMAL input data line.
4) The format for data contained in this file is described in Appendix E of this user's manual.
Description: Specifies the crank angles range for data dumps.
Format: DRANGE ITHS ITHE
Example: DRANGE 350 450
| Variable | Description |
|---|---|
| ITHS | Starting crank angle for data dump. |
| ITHE | Ending crank angle for data dump. |
Notes:
1) If a DRANGE input data line is not included in the input data file, the default value for ITHS is 350 and the default value for ITHE is 370.
2) Only one DRANGE input data line is allowed.
3) This data line is used in conjunction with the DUMPIT input data line.
Description: Selects intermediate analysis results to be printed.
Format: DUMPIT DUMP (1) DUMP ....... DUMP(2) ..... (I)
Example: DUMPIT 20 21
Variable Description
DUMP (i) Code specifying the printed output.
Notes:
1) A list of the printout codes is provided in the description section of each CASE system program. The printout codes are different for each program.
2) The output requested on this input data line is saved in various files which are defined in the description section of each CASE system program.
3) Only one DUMPIT input data line is allowed.
4) Results are provided for crank angles in the range specified on a DRANGE input data line.
Description: Defines end clearance for each ring.
Format: ENDCL EC1 EC2 EC3 EC4
Example: ENDCL 0.002 0.0015 0.0015
| Variable | Description | Units |
|---|---|---|
| EC1 | Top compression ring end clearance. | LENGTH |
| EC2 | Second compression ring end clearance. | LENGTH |
| EC3 | Third compression ring end clearance. | LENGTH |
| EC4 | Oil control ring end clearance. | LENGTH |
Notes:
1) If an ENDCL input data line is not included in the input data file, the end clearance for each ring is zero.
2) If GAPAREA input data line is not included in the input data file, the ring gap areas when the rings are located at the top and the bottom of the grooves are calculted based on ENDCL, CYLBORE, GROOVE, and PISTON input data lines.
3) Only one ENDCL input data line is allowed.
Ring End Clearance
Description: Defines engine speed.
Format: ENGINE SPEED
Example: ENGINE 2500
Variable Description Units
SPEED Engine speed. FREQ
Notes:
1) Only one ENGINE input data line is allowed.
Description: Specifies friction coefficients and pin diameter.
Format: FCOEF CFPL CFPIN
Example: FCOEF 0.1 0.05
| Variable | Description |
|---|---|
| CFPL | Coefficient of friction between piston and cylinder bore. |
| CFPIN | Coefficient of friction between piston and piston pin. |
Notes:
1) If this data line is omitted, the two friction coefficients are set equal to zero.
2) Only one FCOEF input data line is allowed.
Description: Defines lubricant film finite element model.
Format: FEMODEL NEL1 NEL2 NEL3 NEL4
Example: FEMODEL 5 6 2 4
Variable Description
NEL1-NEL4 Finite element model parameters as shown in the figure below.
Notes:
1) This is not a required data line. If it is omitted, NEL1 = NEL2 = 10 and NEL3 = NEL4 = 0.
2) Only one FEMODEL input data line is allowed.
3) The maximum number of node points (NODES) in the finite element mesh must not exceed 144. NODES=(NEL1+1)(NEL2+1) + (NEL3+1)(NEL4)
4) For a full skirt (SHTB = 0.0) NEL3 and NEL4 are not required.
5) In the example below, NEL1 = 5, NEL2 = 6, NEL3 = 2, and NEL4 = 4.
Lubricant Film Finite Element Model
Description: Defines ring gap areas when the rings are located at the top of the grooves.
Format: GAPAREA A1 A2 A3 A4
Example: GAPAREA 0.00029 0.00028 0.0 0.00035
| Variable | Description | Units |
|---|---|---|
| A1 | Gap area - top compression ring. | AREA |
| A2 | Gap area - second compression ring. | AREA |
| A3 | Gap area - third compression ring. | AREA |
| A4 | Gap area - oil control ring. | AREA |
Notes:
1) This input data line defines the ring gap areas when the rings are located at the top of the ring grooves. Gap areas, when the rings are located at the bottom of the ring grooves, are defined on a GAPBOT input data line.
2) If a GAPBOT input data line is not included in the input data file, the gap areas are defined on this GAPAREA input data line are assumed to be the same regardless of the position of the ring in the groove.
3) If GAPAREA input data line is not included in the input data file, the ring gap areas when the rings are located at the top and the bottom of the grooves are calculted based on ENDCL, CYLBORE, GROOVE, and PISTON input data lines.
4) Ring gap areas that vary over the cycle may be defined on GAREA input data lines.
5) Input data lines that define ring gap areas are required only if groove and inter-ring gas pressures are to be calculated.
6) Only one GAPAREA input data line is allowed.
Click here to go to RING GAP AREAS
Ring Gap Area at the top of the Grooves
Description: Defines ring gap areas when the rings are located at the bottom of the grooves.
Format: GAPBOT A1 A2 A3 A4
Example: GAPBOT 0.00029 0.00028 0.0 0.00035
| Variable | Description | Units |
|---|---|---|
| A1 | Gap area - top compression ring. | AREA |
| A2 | Gap area - second compression ring. | AREA |
| A3 | Gap area - third compression ring. | AREA |
| A4 | Gap area - oil control ring. | AREA |
Notes:
1) This input data line defines the ring gap areas when the rings are located at the bottom of the ring grooves. If it is not included in the input data file, ring gap areas, when the rings are located at the bottom of the grooves, are assumed to be equal to ring gap areas when the rings are located at the top of the grooves.
2) Ring gap areas, when the rings are located at the top of the grooves, are defined on a GAPAREA input data line.
3) If GAPAREA input data line is not included in the input data file, the ring gap areas when the rings are located at the top and the bottom of the grooves are calculted based on ENDCL, CYLBORE, GROOVE, and PISTON input data lines.
4) Ring gap areas that vary over the cycle may be defined on GAREA input data lines.
5) Input data lines that define ring gap areas are required only if groove and inter-ring gas pressures are to be calculated.
6) Only one GAPBOT input data line is allowed.
Click here to go to RING GAP AREAS
Ring Gap Area at the bottom of the Grooves
Description: Identifies a data file defining variable ring gap areas.
Format: GAREA RID FILE
Example: GAREA 3 "ch_07_26_02_e.htm#RGA">GA3.DAT
Variable Description
RID Ring identification number (1 RID 4):
1 - Top compression ring.
2 - Second compression ring.
3 - Third compression ring.
4 - Oil control ring.
FILE Name of the data file that contains ring gap areas for ring RID.
Notes:
1) If variable ring gap areas are defined using a GAREA input data line, the ring gap areas specified on GAPAREA and GAPBOT input data lines are ignored.
2) The format for data contained in this file is described in Appendix E of this user's manual.
Description: Defines alternate form of gas flow equation for gas flow through the ring side clearance.
Format: GASFLO DC1 DC2 DC3 DC4
Example: GASFLO 0.86 0.86 0.0 0.86
| Variable | Description |
|---|---|
| DC1 | Discharge coefficient for the top compression ring side clearance. |
| DC2 | Discharge coefficient for the second compression ring side clearance. |
| DC3 | Discharge coefficient for the third compression ring side clearance. |
| DC4 | Discharge coefficient for the oil control ring side clearance. |
Notes:
1) If the GASFLO input data line is not included in the input data file, the flow equation proposed by Namazian and Heywood is used. That equation is:
(m/A) = h2*1/(24WrRT)*(P2u-P2d)
See SAE Paper #820088
2) If this data line is input, the flow equation for flow through the side clearance is identical to the one used for flow through the ring gap. It is:
(m/A) = Cdpcn
3) The discharge coefficient (Cd) for each ring may be specified. The default value for each ring is 0.65.
4) Only one GASFLO input data line is allowed.
Description: Identifies the file containing combustion chamber gas pressure data.
Format: GASPRES FILE
Example: GASPRES "ch_07_26_02_e.htm#CGP">GASPR.DAT
Variable Description
FILE Name of the data file that contains combustion chamber gas pressure data.
Notes:
1) If a GASPRES input data line is not included in the input data file, either the combustion, groove and inter-ring gas pressures are assumed to be atmospheric for the entire cycle or gas pressures calculated during a previous analysis have been saved and input for use in the present analysis.
2) Only one GASPRES input data line is allowed.
3) Groove and inter-ring gas pressures are considered in the analysis if either a GASPRES or a PRESURE input data line is included in the input data file. If a GASPRES input data line is included, groove and inter-ring gas pressures are computed. If a PRESURE input data line is included, results from a previous analysis are used.
4) Gas pressures are defined for the entire cycle.
5) The format for data contained in this file is described in Appendix E of this user's manual.
Description: Provides estimates of lubricant flow through ring gaps and grooves for lubricant starvation analyses.
Format: GFLOW FLOR FLCR1 FLCR2 FLCR3
Example: GFLOW 10E-6 50 50
| Variable | Description | Units |
|---|---|---|
| FLOR | Lubricant flow through oil control ring. | LENGTH |
| FLCR1 | Lubricant flow through top compression ring groove (percentage of lubricant accumulated between top ring and second ring). | none |
| FLCR2 | Lubricant flow through second compression ring groove (percentage of lubricant accumulated between second ring and third ring). | none |
| FLCR3 | Lubricant flow through third compression ring groove (percentage of lubricant accumulated between third ring and oil control ring). | none |
Notes:
1) If this data line is not included in the input data file, lubricant flows through the grooves and gaps of all rings are assumed to be zero.
2) Only one GFLOW input data line is allowed.
Description: Defines piston groove geometry for a compression or oil control ring.
Format: GROOVE GID GH GW TOPANG BOTANG GDIA
Example: GROOVE 2 0.065 0.150 0.0 0.0 3.5
| Variable | Description | Units |
|---|---|---|
| GID | Groove identification number (1 GID 4): | none |
| none | 1 - Top compression ring groove. | none |
| none | 2 - Second compression ring groove. | none |
| none | 3 - Third compression ring groove. | none |
| none | 4 - Oil control ring groove. | none |
| GH | Groove height. | LENGTH |
| GW | Groove width. | LENGTH |
| TOPANG | Angle at top of groove. | ANGLE |
| BOTANG | Angle at bottom of groove. | ANGLE |
| GDIA | Groove inside diameter. | LENGTH |
Notes:
1) A GROOVE input data line is required for each ring specified on a RINGPAC input data line.
2) A GDIA is an optional data entry. If GDIA is not specified, GDIA dimension is calculated based on groove width GW and piston diameter PDIA from PISTON data line. If GDIA is specified, the land diameter below the ring is calculated based on groove width GW and groove inside diameter GDIA .
Piston Groove Geometry
Description: Specifies a leakage area between a ring and top of groove.
Format: LEAKAGE LK1 LK2 LK3 LK4
Example: LEAKAGE 0.05 0.07
| Variable | Description |
|---|---|
| LK1 | Leakage ratio for upper side of top compression ring. |
| LK2 | Leakage ratio for upper side of second compression ring. |
| LK3 | Leakage ratio for upper side of third compression ring. |
| LK4 | Leakage ratio for upper side of oil control ring. |
Notes:
1) Whenever a ring is seated against the top or bottom of its groove, a perfect seal is normally assumed.
2) The LEAKAGE input data line allows the user to specify a gas leakage area through the groove when a ring is seated against the top of the groove. The leakage area for the top compression ring is (PW1)leak = LK1*PW1, for the second compression ring it is (PW2)leak = LK2*PW2, etc.
3) A perfect seal is still assumed when rings are seated on the bottom of the groove.
4) Only one LEAKAGE input data line is allowed.
Leakage area between a ring and top of groove
Description: Defines the location of a port in a two stroke engine.
Format: LPORT LOC
Example: LPORT 3.5
Variable Description Units
LOC Location of port from top of deck. LENGTH
Notes:
1) The pressure at the port is always assumed to be atmospheric. Once the lower ring of an inter- ring volume is below the top of the port location, the pressure for the inter-ring volume is zero.
2) Mass flow through the ring pack is the flow through the ring grooves and gaps and does not consider gas flow through the port.
Port location in a two-stroke engine
Description: Defines the type of rear bounadary conditions to be used for ring lubrication analyses.
Format: LUBBC KODE
Example: LUBBC 2
Variable Description
KODE Code specifying boundary condition:
0 - Half Sommerfeld (ventilation).
1 - Half Sommerfeld (separation).
2 - Reynolds (ventilation).
3 - Reynolds (separation).
Notes:
1) If this input data line is not included in the input data file, the Half Sommerfeld ventilated boundary condition is used.
2) Only on LUBBC input data line is allowed.
Description: Defines piston mass and mass moment of inertia.
Format: MASSES MPIN MPIS PISICG
Example: MASSES 1.878 2.80 0.016
| Variable | Description | Units |
|---|---|---|
| MPIN | Mass of piston pin and retainers. | MASS |
| MPIS | Mass of piston and rings. | MASS |
| PISICG | Mass moment of inertia of piston about piston C.G. | MMOI |
Notes:
1) Only one MASSES input data line is allowed.
Description: Defines the properties of a material.
Format: MATL MID E PR DENS K ALPHA
Example: MATL 897 29.95E6 0.27 7.58E-4 0.54 7.66
| Variable | Description | Units |
|---|---|---|
| MID | Material identification number (50). | none |
| E | Modulus of elasticity. | MODULUS |
| PR | Poisson's ratio. | none |
| DENS | Mass density. | DENS |
| K | Conduction coefficient. | CONDUCT |
| ALPHA | Coefficient of thermal expansion. | COEFTE |
Notes:
1) The total number of materials defined on MATL input data lines must not exceed 10.
2) Material identification numbers 1 through 50 are reserved for materials which have their properties stored in the material library (MATL.LIB).
3) Material properties stored in the material library may be modified. Additional materials may also be added to the library.
Description: Defines constants in a viscosity vs. temperature equation.
Format: OILFUNC KODE a b c
Example: OILFUNC 2 0.0196 1518.0 122.6 3
Variable Description
KODE Code specifying the viscosity equation:
1 - Slotte's Equation
2 - Vogel's Equation
a, b, c Constants in the viscosity equation
Notes:
1) The relationship between oil viscosity and temperature can be defined on an OILFUNC, OILPROP, or OILTYPE input data line. Only one of these input data lines is allowed.
2) If an OILFUNC, c, or OILTYPE data line is not input, oil viscosity is assumed to be zero (i.e., an unlubricated cylinder).
3) Slotte's viscosity equation is given as:
= a/(b+t)c
4) Vogel's viscosity equation is given as:
= ae(b/t+c)
5) In both of the equations above,
= dynamic viscosity (cP)
t = temperature (oC)
a, b, c, = constants.