Introduction

Background

Objectives


Test facility

Diagnostic techniques


Cross-flow influence

Overall boiling curves

Intermittent cooling efficiency

Heat transfer correlations






 

 
Advances in Intermittent Spray Impact Research

micro nano engineering
   

  Introduction

A renewable interest is now arising on port fuel injection as a way to achieve homogeneous premixing for ultra lean combustion strategies, either of diesel or of gasoline fuels, namely HCCI. Although there is ample evidence that HCCI combustion in four-stroke engines is dominated by chemical kinetics, experiments indicate that mixture inhomogeneity plays an important role in HCCI combustion and is a key enabler for controlling HCCI combustion.


  The potential of spray impingement to remove large amounts of energy at low temperatures through the latent heat of evaporation is used in a wide range of engineering systems. Technological applications include those geared for surface cooling, such as metal foundries, high power electronic devices, or the skin in dermatologic laser surgery; or to promote fuel vaporization and gaseous mixing in internal combustion engines, either reciprocating or premixed-prevaporizing gas turbines.

The common research ground is the thermal and fluid dynamics associated with impinging sprays which is both intellectually interesting and technologically challenging. The implications of its fundamental knowledge involve better environmental protection and engine performance in the case of fuel sprays, better thermal management systems for increasing computational performance and better medical technology for human healthcare.

Projects

“Advanced Intermittent Spray Cooling Systems”
Project PTDC/EME-MFE/69459/2006 sponsored by FCT (2007-2010)

“Dynamic behaviour of cryogen spray cooling”
Project POCTI/EME/57944/2004 sponsored by FCT (2005-2008)

“Fluid-Particle correlations in Non-homogeneous Turbulent Two-Phase Flows”
Project POCTI/2001/EME/38082 sponsored by FCT (2002-2005)

“Flow and heat transfer characteristics of evaporating impinging sprays”
Project POCTI/1999/EME/32960 sponsored by FCT (2001-2004)

“Direct Injection engine Spray Processes – Mechanisms to Improve Performance”
ENK6-CT-2000-00101 sponsored by FP5 (2000 – 2003)