Heat transfer and flow velocity study of a row of jets emerging from a perforated pipe at a low Reynolds number

Yassine Ahmimache (1, 2) , Matthieu Fénot (2) , Frédéric Plourde (2) , Laurent Descamps (1)

1 Safran Aircraft Engines, Centre de Villaroche, Moissy Cramayel 77550, France
2 COST - Convection, Optimisation, Systèmes Thermiques [Institut Pprime]

Aerodynamic and thermal experimental investigations were carried out on a row of circular low Reynolds jets emerging from a perforated pipe. Particle Image Velocimetry and Infrared Thermography were performed to determine flow velocity fields and local Nusselt number variations along the impinged plate. Jet Reynolds number (), upstream crossflow in the pipe (), injection-to-plate distance () as well as center-to-center jet spacing () were all taken into account. Measurements were compared to those of a fully developed circular jet issuing from a long tube under the same conditions ( and ). Experimental results showed that jets tend to emerge with an effective cross-sectional area reduced to a crescent shape unlike that of axisymmetric fully developed jets; their specific structure was attributed to flow deflection from the pipe to the holes and resulted in heat transfer specificities differing from those of a fully developed jet. Heat transfer rates were found to be primarily dependent on injection Reynolds number, injection-to-plate distance and center-to-center spacing, and they were found to be relatively low compared to a fully developed jet.

Mots clés: Jet impingement cooling; Row of jets; Single jet; Crossflow; Heat transfer coefficient; Infrared thermography; PIV

Domaines: Physique [physics]

Yassine Ahmimache, Matthieu Fénot, Frédéric Plourde, Laurent Descamps. Heat transfer and flow velocity study of a row of jets emerging from a perforated pipe at a low Reynolds number. International Journal of Heat and Mass Transfer, 2022, 183, pp.122067. ⟨10.1016/j.ijheatmasstransfer.2021.122067⟩. ⟨hal-03617210⟩