Input Data Line: RINGPAC
Description: Defines the number of rings in the ring pack.
Format: RINGPAC NUMCR NUMOR
Example: RINGPAC 2 1
| Variable | Description |
|---|---|
| NUMCR | Number of compression rings in the ring pack (1 NUMCR 3). |
| NUMOR | Number of oil control rings in the ring pack (0 NUMOR 1). |
Notes:
1) Compression ring cross sections are defined on RSECT and RINGMOD input data lines.
2) Oil control ring cross sections are defined on an OILRING input data line.
3) Ring face profiles for compression rings and oil control ring segments (or lands) are defined on RFACE1 through RFACE7 input data lines.
4) Ring materials are defined on RMATL input data lines.
5) Ring tensions are defined on RINGTEN input data lines.
6) The mass of each ring is defined on an RMASS input data line.
Description: Identifies the file containing compression ring pressure shape data.
Format: RINGPS RID FILE
Example: RINGPS 3 PR3.DAT
| Variable | Description |
|---|---|
| RID | Ring identification number (1 RID 3): |
| none | 1 - Top compression ring. |
| none | 2 - Second compression ring. |
| none | 3 - Third compression ring. |
| FILE | Name of the data file that contains pressure shape data for ring RID. |
Notes:
1) Compression rings are assumed to have a uniform pressure distribution unless RINGPS input data lines are included in the input data file.
2) The format for data contained in this file is described in Appendix E of this users' manual.
Description: Defines the tension in a compression or oil control ring.
Format: RINGTEN RID RTEN
Example: RINGTEN 1 9.3
| Variable | Description | Units |
|---|---|---|
| RID | Ring identification number (1 RID 3): | none |
| none | 1 - Top compression ring. | none |
| none | 2 - Second compression ring. | none |
| none | 3 - Third compression ring. | none |
| none | 4 - Oil control ring. | none |
| RTEN | Diametral tension in ring. | FORCE |
Notes:
1) If ring tension is not defined on a RINGTEN input data line, it is assumed to be zero.
2) Diametral tension is related to tangential tension according to the approximate formula: Dt = 2.1Tt
Description: Defines ring locations from top of piston.
Format: RLOCATE Y1 Y2 Y3 Y4
Example: RLOCATE 0.5 0.85 0 1.3
| Variable | Description | Units |
|---|---|---|
| Y1 | Distance from top of piston to top compression ring. | LENGTH |
| Y2 | Distance from top of piston to second compression ring. | LENGTH |
| Y3 | Distance from top of piston to third compression ring. | LENGTH |
| Y4 | Distance from top of piston to oil control ring. | LENGTH |
Notes:
1) Only one RLOCATE input data line is allowed.
Ring locations from top of piston
Description: Specifies the mass of a piston ring.
Format: RMASS RID MASS
Example: RMASS 1 0.025
| Variable | Description | Units |
|---|---|---|
| RID | Ring identification number (1 RID 3): | none |
| none | 1 - Top compression ring. | none |
| none | 2 - Second compression ring. | none |
| none | 3 - Third compression ring. | none |
| MASS | Piston ring mass. | LENGTH |
Notes:
1) An RMASS input data line is required for each piston ring in the ring pack. The number of piston rings is specified on a RINGPAC input data line.
Description: Specifies a piston ring material.
Format: RMATL RID MID
Example: RMATL 1 12
| Variable | Description |
|---|---|
| RID | Ring identification number (1 RID 5): |
| none | 1 - Top compression ring. |
| none | 2 - Second compression ring. |
| none | 3 - Third compression ring. |
| none | 4 - Oil control ring (expander for a three-piece oil control ring). |
| none | 5 - Oil control ring segments (for a three-piece oil control ring). |
| MID | Piston ring material identification number. |
Notes:
1) The ring material identification number (MID) refers to a material defined on a MATL input data line or a material defined in the material libraryl. If the material is in the material library, then 1 MID 50. If the ring material is defined on a MATL input data line, then MID must correspond to the MID on the MATL input data line.
Description: Specifies a connecting rod material.
Format: RMATL MID
Example: RMATL 12
Variable Description
MID Connecting rod material identification number.
Notes:
1) The connecting rod material identification number (MID) refers to a material defined on a MATL input data line or a material defined in the material library. If the material is in the material library, then 1 MID 50. If the connecting rod material is defined on a MATL input data line, then MID must correspond to the MID on the MATL input data line.
Description: Defines the cross-sectional properties of a compression ring.
Format: RSECT RID RT RW ANGTOP ANGBOT
Example: RSECT 3 0.057 0.1 7.5 7.537
| Variable | Description | Units |
|---|---|---|
| RID | Ring identification number (1 RID 3): | none |
| none | 1 - Top compression ring. | none |
| none | 2 - Second compression ring. | none |
| none | 3 - Third compression ring. | none |
| RT | Ring width. | LENGTH |
| RW | Ring radial wall. | LENGTH |
| ANGTOP | Top keystone angle. | ANGLE |
| ANGBOT | Bottom keystone angle. | ANGLE |
Notes:
1) An RSECT input data line is required for each compression ring in the ring pack. The number of compression rings is specified on a RINGPAC input data line.
2) Internal bevels or internal steps are defined on RINGMOD input data lines.
Cross-sectional properties of a compression ring
Description: Defines the ring section properties of a piston ring.
Format: RSPROP RID A Ix Iy Ixy J XCG YCG
Example: RSPROP 3 0.0165 3.9E-5 1.4E-5 -1.8E-6 1.8E-07 0.003 0.001
| Variable | Description | Units |
|---|---|---|
| RID | Ring identification number (1 RID 5): | none |
| none | 1 - Top compression ring. | none |
| none | 2 - Second compression ring. | none |
| none | 3 - Third compression ring. | none |
| none | 4 - Oil control ring. | none |
| A | Cross-sectional area of ring. | AREA |
| Ix | Moment of inertia of ring about X-----X axis. | SMOI |
| Iy | Moment of inertia of ring about Y-----Y axis. | SMOI |
| Ixy | Product of inertia about C.G. of cross section of ring. | SMOI |
| J | Torsional constant of cross section of ring. | SMOI |
| XCG | X distance of the ring cross section CG relative to the bottom internal edge. | LENGTH |
| YCG | Y distance of the ring cross section CG relative to the bottom internal edge. | LENGTH |
Notes:
1) The cross-sectional properties for each compression ring in the ring pack are defined on RSPROP input data lines.
2) If the ring cross-sectional properties of a compression ring are not specified, the ring is assumed to be rectangular with the width and radial wall defined on an RSECT input data line. Section properties will be calculated based on these dimensions.
3) An RSPROP input data line is required for an oil control ring. 4) Only one RSPROP input data line is allowed for each compression ring.
Ring section properties of a piston ring
Description: Identifies the file containing ring temperature data.
Format: RTEMP RID FILE
Example: RTEMP 2 RTEMP.DAT
| Variable | Description |
|---|---|
| RID | Ring identification number (1 RID 3): |
| none | 1 - Top compression ring. |
| none | 2 - Second compression ring. |
| none | 3 - Third compression ring. |
| FILE | Name of the data file that contains ring temperature data. |
Notes:
1) The format for data contained in this file is described in Appendix E of this user's manual.
Ring temperature data
Description: Defines the ring twist angles.
Format: RTWIST RID RTA1 RTA2
Example: RTWIST 1 0.020 0.005
| Variable | Description | Units |
|---|---|---|
| RID | Ring identification number (1 RID 3): | none |
| none | 1 - Top compression ring. | none |
| none | 2 - Second compression ring. | none |
| none | 3 - Third compression ring. | none |
| RTA1 | Ring twist angle due to non-symmetric shape of ring cross section. | ANGLE |
| RTA2 | Ring twist angle due to non-symmetric temperature distribution through the ring. | ANGLE |
Notes:
1) Only one RTWIST data line is allowed for each ring with non-zero twist angle
2) Twist angles are positive counterclockwise as shown in the figure below and are assumed constant around the entire circumference of the ring.
3) Groove geometry and ring geometry limit the ring twist angles. The user should not specify twist angles that cannot occur. The RING program checks for user errors.
Ring twist angles
Description: Creates an output file containing combustion gas pressures and groove and inter-ring gas pressures calculated by the CASE system program RING.
Format: SAVEPR FILE
Example: SAVEPR GASES.PRE
Variable Description
FILE Name of the file containing combustion gas pressures and computed groove and inter- ring gas pressures.
Notes:
1) If a SAVEPR input data line is not included in the input data file, the groove and inter-ring gas pressures calculated by the CASE system program RING will not be saved. If a SAVEPR input data line is included in the input data file, the combustion gas pressure and the groove and inter-ring gas pressures calculated by the RING program will be saved in the data file named on this input data line.
2) Only one SAVEPR input data line is allowed.
3) The SAVPR input data line is used in conjunction with the GASPRES input data line. If a GASPRES input data line is not input, the SAVEPR input data line will be ignored.
4) The format for data saved in this file is described in Appendix F of this user's manual.
Description: Creates an output file containing piston tilt angles calculated by the CASE system program PISTON.
Format: SAVETA FILE
Example: SAVETA PTA.DAT
Variable Description
FILE Name of the file containing piston tilt angle data.
Notes:
1) If a SAVETA input data line is not included in the input data file, the piston tilt angles calculated by the CASE system program PISTON will not be saved. If a SAVETA input data line is included in the input data file, the piston tilt angles calculated by the PISTON program will be saved in the data file named on this input data line.
2) Only one SAVETA input data line is allowed.
Description: Defines the seating parameters for a piston ring.
Format: SEATING RID K1 K2
Example: SEATING 3 0.3 0.5
| Variable | Description |
|---|---|
| RID | Ring identification number (1 RID 4): |
| none | 1 - Top compression ring. |
| none | 2 - Second compression ring. |
| none | 3 - Third compression ring. |
| none | 4 - Oil control ring. |
| K1 | Seating parameter |
| K2 | Seating parameter |
Notes:
1) If the seating parameters of a piston ring are not defined, the default values for the ring are K1 = K2 = 0.33
2) Only one SEATING input data line is allowed for each ring specified on a RINGPAC input data line.
3) Values of K1 and K2 must range between 0.0 and 1.0 and K2 K1.
4) The seating parameters are used to determine axial pressure loads on the rings. These loads influence axial movement in the groove.
Seating parameters for a piston ring
Description: Defines the piston skirt geometry.
Format: SKIRT SHT SW SW1 SW2
Example: SKIRT 2.2 3.0 1.5 0.8
| Variable | Description | Units |
|---|---|---|
| SHT | Skirt height. | (LENGTH) |
| SW | Skirt width. | (LENGTH) |
| SHTB | Skirt dimension (See figure below). | (LENGTH) |
| SW1 | Skirt dimension (See figure below). | (LENGTH) |
| SW2 | Skirt dimension (See figure below). | (LENGTH) |
Notes:
1) Only one SKIRT input data line is allowed
2) The piston diameter (PDIA) and piston height (PHT) are defined on a PISTON input data line.
3) If SHTB = 0.0 (full skirt), SW1 and SW2 are not required.
Piston skirt geometry
Description: Defines several parameters in a Stribeck diagram.
Format: STRIBEK FB R1 R2
Example: STRIBEK 0.11 1 7
| Variable | Description |
|---|---|
| FB | Coefficient of friction for boundary lubrication. |
| R1 | Ratio of effective oil film to surface roughness when boundary lubrication begins. |
| R2 | Ratio of effective oil film to surface roughness when mixed lubrication begins. |
Notes:
1) If a STRIBEK input data line is not included in the input data file, the default parameters are:
FB = 0.10
R1 = 1
R2 = 5
2) Only one STRIBEK input data line is allowed.
Several parameters in a Stribeck diagram
R = Effective Oil Film/Surface Roughness Viscosity
() * Speed (U)/Load (L)
Description: Defines the sump pressure.
Format: SUMPPRE SP
Example: SUMPPRE
Variable Description Units
SP Sump pressure. PRESS
Notes:
1) If a STRIBEK input data line is not included in the input data file, the sump pressure is equal to 0 psig (14.7 psia).
2) Only one SUMPPRE input data line is allowed.
Description: Defines the surface roughness of the piston rings, cylinder bore and piston skirt.
Format: SURFACE SID ROUGH
Example: SURFACE 6 15.0E-6
Variable Description Units
SID Surface identification number (1 SID 6): none
1 - Top compression ring.
2 - Second compression ring.
3 - Third compression ring.
4 - Oil control ring segments (or lands).
5 - Piston Skirt
6 - Cylinder Bore.
ROUGH Roughness value. LENGTH
Notes:
1) Surface roughness must be at least 1 microinch (0.025 micrometer).
2) The default surface roughness is 6 microinches (0.15 micrometer) for the cylinder bore and 5 microinches (0.125 micrometer) for each ring face and the piston skirt.
Surface roughness of piston rings, cylinder bore and piston skirt
Description: Identifies the file containing thermal bore distortion data.
Format: THERMAL FILE
Example: THERMAL TDIST.DAT
Variable Description
FILE Name of the data file that contains thermal bore distortion data.
Notes:
1) If a THERMAL input data line is not included in the input data file, thermal bore distortions will not be considered in the analysis.
2) Only one THERMAL data line is allowed.
3) Thermal bore distortions are defined in the data file identified on this input data line. These distortions are caused by temperature gradients in the block or liner. Mechanical bore distortions are defined in a file identified on the DISTORT input data file.
4) The format for data contained in this file is described in Appendix E of this user's manual.
Description: Defines an analysis title.
Format: TITLE1 TITLE1INFO
Example: TITLE1 THIS IS A TITLE DATA LINE.
Variable Description
TITLE1INF Title of analysis to appear on O printed output and plots.
Notes:
1) Only one TITLE1 input data line is allowed.
2) The default title is blank.
Description: Defines an analysis subtitle.
Format: TITLE2 TITLE2INFO
Example: TITLE2 THIS IS A SUBTITLE DATA LINE.
Variable Description
TITLE2INF Subtitle of analysis to appear on O printed output and plots.
Notes:
1) Only one TITLE2 input data line is allowed.
2) The default subtitle is blank.
Description: Identifies a ring twist data file.
Format: TWISTFL RID TWISTFILE
Example: TWISTFL 1 TWIST01.TWS
Variable Description
| Variable | Description |
|---|---|
| RID | Ring identification number (1 RID 3): |
| none | 1 - Top compression ring. |
| none | 2 - Second compression ring. |
| none | 3 - Third compression ring. |
| FILE | Name of the ring twist data file. |
Notes:
1) For the TWIST program, the twist analysis will be performed for the ring RID and the results will be saved in the file TWISTFILE .
2) For the RING program, the ring motion the ring RID will be calculated using the ring twist data read from the file TWISTFILE .
Description: Defines the default sysytem of units for input data and output results.
Format: UNITS INPUT OUTPUT
Example: UNITS 2 1
Variable Description
INPUT Unit system code for input data:
1 - English System.
2 - SI System
3 - MKS System
4 - CGS System
5 - User defined system.
6 - User defined system.
OUTPUT Unit system code for output results:
1 - English System
2 - SI System
3 - MKS System
4 - CGS System
5 - User defined system.
6 - User defined system.
Notes:
1) If a units data line is not included in the input data file, the default system of units for input data and output results is the SI System, i.e., INPUT = OUTPUT = 2.
2) Unit default values for the four basic systems of units are defined in the table on the following page.
3) User defined systems of units (5 and 6) may be created using the procedures described in the CASE Programmer's Manual.
Description: Defines land and groove volumes
Format: VOLUME V1 V2 V3 V4 V5 V6 V7
Example: VOLUME 0.010 0.015 0.013
Variable Description UNITS
V1-V7 Land and groove volumes. (see figure below) VOLUME
Notes:
1) This data line isoptinal if groove and inter-ring gas pressures are to be calculated. If VOLUME input data line is not specified, the inter-ring volumes are calculted based on the ring / ring pack dimensions provided in the GROOVE, RSECT, CYLBORE, and PISTON input data lines.
2) Only one VOLUME input data line is allowed.
3) For J rings, 2J -1 crevice volumes must be defined.
4) If the ring pack consists of two compression rings and an oil control ring, V5=V6=0. All other volumes must be specified. For one compression ring and an oil control ring, V3=V4=V5=V6=0. All other volumes must be specified.
Land and groove volumes
