FLOW STRUCTURES AND HEAT TRANSFER IN SUBMERGED LAMINAR JET IMPINGEMENT

Wilko Rohlfs
Institute of Heat and Mass Transfer, RWTH Aachen University, 52062 Aachen, Germany

Johannes Jorg
Institute of Heat and Mass Transfer, RWTH Aachen University, Aachen, 52056, Germany

Claas Ehrenpreis
Institute of Heat and Mass Transfer, RWTH Aachen University, Aachen, 52056, Germany

Manuel Rietz
Institute of Heat and Mass Transfer, RWTH Aachen University, Aachen, 52056, Germany

Herman D. Haustein
School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel; Institute of Heat and Mass Transfer, RWTH Aachen University, 52062 Aachen, Germany

Reinhold Kneer
Institute of Heat and Mass Transfer, RWTH Aachen University, Augustinerbach 6, 52056 Aachen, Germany

DOI: 10.1615/TFESC1.fnd.012816
pages 1011-1020

KEY WORDS: Convection, Two-phase/Multiphase, Heat transfer enhancement

Abstract

Impinging jets are well known for their high heat/mass transfer rates, widely employed in industrial cooling and drying processes and as such have been investigated extensively. The present paper provides a comprehensive description of laminar free-surface and submerged impinging jets by summarizing the understanding gained in recent studies by the authors. In a previous study, a correlation was formulated for free-surface and submerged jets. However, the validity of the correlation was limited to idealized conditions, e.g. the absence of vortices. This paper experimentally and numerically examines the flow field of submerged jets under the presence of low amplitude perturbations, showing different types of vortex structures and mechanisms of jet breakup.