An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A flow in which the velocity of the constituting particles never exceeds that of sound in the same fluid. Also called subcritical flow.

→ subsonic; → flow.

The → Couette flow between two concentric cylinders with fluid filling the annular region. The flow is generated by the relative rotation of the two cylinders. Under some physical conditions the flow may undergo the → Taylor-Couette instability.

→ Taylor number; → flow.

A flow whose parameters (velocity, pressure, and so on) vary in all three coordinate directions. Considerable simplification in analysis may often be achieved, however, by selecting the coordinate directions so that appreciable variation of the parameters occurs in only two directions, or even only one (B. Massey, Mechanics of Fluids, Taylor & Francis, 2006).

→ three; → dimensional; → flow.

In fluid mechanics, a flow composed of → laminar and → turbulent flows, for which the → Reynolds number is between 2300 and 4000.

→ transition; → flow.

Flow of a fluid over a body with a speed in the range just above and below the → Mach number 1.

→ transonic; → flow.

Same as → flow tube.

→ tube; → tube.

A → flow characterized by → turbulence. In other words, a flow in which the motion at any point varies unpredictably in direction and magnitude. See also → laminar flow; → transitional flow.

→ turbulent; → flow.

A flow whose parameters are functions of time and two space coordinates (x and y) only. There is no variation in the z direction and therefore the same → streamline pattern could at any instant be found in all planes in the fluid perpendicular to the z direction (B. Massey, Mechanics of Fluids, Taylor & Francis, 2006).

→ two; → dimensional; → flow.