# POLYPHASE

More than one phase or sine wave is generated. Some generators produce two, or more often, three phase power.

## Related Terms

### MULTIPHASE FRACTION METER

A device for measuring the phase area fractions of oil, gas and water of a multiphase flow through a cross-section of a conduit.

### PHASE FLOW RATE

The amount of one phase of a multiphase flow flowing through the cross-section of a conduit in unit time. The phase flow rate may be specified as phase volume flow rate or as phase mass flow rate.

### SLIP VELOCITY

The phase velocity difference between two phases.

### SLIP RATIO

The ratio between two phase velocities.

### MULTIPHASE FLOW

Two or more phases flowing simultaneously in a conduit; this document deals in particular with multiphase flows of oil, gas and water.

### MULTIPHASE METER

A device for measuring the phase area fractions and flow rates of oil, gas and water of a multiphase flow through a cross-section of a conduit. It is necessary to specify whether the multiphase meter measures volume or mass flow rates.

### PHASE VELOCITY

The velocity of one phase of a multiphase flow at a cross-section of a conduit. It may also be defined by the relationship (Superficial phase velocity * Phase area fraction).

### SUPERFICIAL PHASE VELOCITY

The flow velocity of one phase of a multiphase flow, assuming that the phase occupies the whole conduit by itself. It may also be defined by the relationship (Phase volume flow rate / Pipe cross-section).

### MIXTURE PHASE

In this document, “phase” is used in the sense of one constituent in a mixture of several. In particular, the term refers to either oil, gas or water in a mixture of any number of the three.

### PHASE VOLUME FRACTION

The phase volume flow rate of one of the phases of a multiphase flow, relative to the multiphase volume flow rate.