Share

Analysis of a low Reynolds jet flow from a notched orifice jet for HVAC applications.

Number: pap. 79

Author(s) : GREFFET R., MESLEM A., NASTASE I.

Summary

The flow in the initial region of a notched orifice jet is experimentally analyzed and compared to a circular orifice jet. The equivalent diameter (De) of each orifice is 10 mm. The initial Reynolds number based on De was around 800 for both jets. Flows exploration has been achieved using flow visualization, Particle Image Velocimetry, Laser Doppler Anemometry as well as Hot-Wire Anemometry. The aimed applications are mixing ventilation and personalized ventilation (PV). Our previous investigation of elementary orifice cross-shaped jet and its integration in the design of innovative air diffusion terminal units confirm the advantage of passive mixing control using lobed orifices. The present geometry manipulation extends the passive control to rectangular jets sometimes preferred in the design of HVAC terminal units. The axis-switching phenomenon observed earlier in the cross-shaped jet, disappears in the notched orifice jet. The streamwise structures that develop in orifice troughs do not modify the overall transverse direction of the notched jet. This can be an advantage in PV which must provide a jet flow that covers the breathing zone of the user. Velocity fields show that the jet potential core length is shorter in the notched orifice jet compared to the circular orifice jet. The potential core length is quantified to about 2De in the notched jet and to 5De in the reference circular jet. This is due to a larger ambient-air entrainment in the former with comparison to that in the latter.

Available documents

Format PDF

Pages: 10 p.

Available

  • Public price

    20 €

  • Member price*

    15 €

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).

Details

  • Original title: Analysis of a low Reynolds jet flow from a notched orifice jet for HVAC applications.
  • Record ID : 30008580
  • Languages: English
  • Source: Clima 2013. 11th REHVA World Congress and 8th International Conference on Indoor Air Quality, Ventilation and Energy Conservation in Buildings.
  • Publication date: 2013/06/16

Links


See other articles from the proceedings (424)
See the conference proceedings

Indexing