Is there other uses of flow-straighteners than flow-metering? Flow-straighteners are used before flow-meters because they remove disturbances from the flow and achieve nearly-fully developped velocity profiles. But is there any other uses of flow straighteners than flow-metering ? Car companies like Mitsubishi, for instance, developped their own models of flow straighteners, what for ?
 A: Flow straighteners are also used in experimental setups, where a uniform flow free of swirl is required. Swirl can be induced notably by a motor. This could be important in wind tunnel design, or study of liquid flows in ducts.
In order to properly remove swirl, honeycomb designs having cell lengths at least 6-8 times their diameter should be used, see reference.

The aerodynamic design of blower tunnels with wide-angle diffusers. R.D. Mehta. Progr. Aerospace Sci. 18, pp. 59-120 (1979).

A: Jet pipe is employed in turbo-jet engine. It is situated before afterburner and after the turbine.  It (among all the other functions) also acts as the flow straightener.
Wind tunnels have the flow straightener before the nozzle. It is very important for a wind tunnel to have a flow straightener, so that the test section has as less turbulence as possible. 
A: Widely used in any lab where techs need easy access, but don't want the air in the cabinet mixing with the air in the room.  The goal is to have a steady flow  past the equipment, with a slight overpressure so some air diverts into room.  Google "laminar flow cabinet"
This link http://poweredaire.com/air_curtains_101 mentions laminar flow used in creating air curtains.
A: I don't know if this counts as a "use", but check out this fountain at the Detroit airport.
