Compute Volumetric Efficiency. This version (volef2) uses a spec file into which you specify an engine displacement variable rather than the number of cylinders.  This can be used for computing the volumetric efficiency of a bank of engines (say 6 cylinders of a 12 cylinder engine), or can be used for computing the volumetric efficiency of a 2-cycle engine by entering double the actual engine displacement.


volef2 <priority> <interval> <filename> [+c]



Specify the system task priority.


Specify the task process interval. Specify FAS, MED, or SLO. The interval value can be in milliseconds or be one of the interval strings such as FAS, MED, or SLO. The values of “FAS”, “MED”, and “SLO” are defined by the spawning arguments of the “scheduler” task.  Enter ‘sin -Pscheduler ar’ to see the actual millisecond values.


Specify the fully qualified specification file path and name.


Optional. Specify this flag to identify this task as critical to the watchdog.


volef2 8 SLO /specs/volef2_specs.315 +c &

The above command spawns ‘volef2’ in the background at a priority of 8. The computations are performed once every second using the specifications given in the file /specs/volef2_specs.315. The task is also assigned to be a critical task. As a result, if the task ever stops responding to the watchdog, any test that is running will be aborted.

The volef2 task will register it’s name with the filename (not the full pathame), in this case “volef2_specs.315”.  This name can be used by the ‘re-read’ command to request that it update the specifications by reading the specification file again.  This feature allows the specifications to be changed “on-the-fly” without slaying and restarting the app. Note: re-read feature is not available prior to 6.3.30 or 6.4.0.


          In the specification file, the field for specifying the engine displacement can be entered as either a variable label such as “dspl” or as a value token such as “10[l]”.  For computing to volumetric efficiency of a manifold that is feed only part of an engine, enter the displacement value that                        represents the displacement value of the cylinders fed by the manifold

          For 2-cycle engines, the value of (2*displacement) is entered as an actual value in the specification file.  For example:  10[l] for a 5 liter engine.

This task is normally started in the go script that starts CyFlex.  Multiple copies may be running, each with a different specification file.

See Also:

Computing Volumetric Efficiency, also see /cyflex/specs.def/volef2def for example spec