Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
5th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xian, China, 36 July 2005
 

Summary: 5th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion
Xian, China, 36 July 2005
Uniform Heat Transfer of Medical Cryogen Sprays through Wire Meshes
Walfre FRANCO1, Hong HAN1, Guo-Xiang WANG2, and Guillermo AGUILAR1
1. Laboratory of Transport Phenomena for Biomedical Applications
Department of Mechanical Engineering, University of California, USA
2. Department of Mechanical Engineering, University of Akron, USA
Abstract. Cryogen spray cooling (CSC) protects the epidermal layer during dermatologic laser surgery (DLS) of superficial
vascular lesions. Because of spray characteristics the protection provided radially is relatively uniform only by the spray axis. The
present work explores mass-deposition passive-control during CSC in order to increase the radial homogeneity of heat extraction.
A stainless steel mesh is placed 5 and 10 mm away from the nozzle tip of the spray system, and a fast-response thermal sensor
is used to measure temperatures across the radius of the sprayed surface of a human skin phantom. Surface measurements along
with an analytical expression are used to compute heat fluxes. Lower temperatures and higher heat fluxes are obtained without
the mesh. Consequently, the mesh quantitatively reduces cooling. However, radial distributions of temperature and heat flux
show that more uniform heat transfer in time and space takes place using the mesh. Evolution of temperatures in time and space
shows that the mesh introduces a thermal delay, which may be used to compensate for the reduction in cooling. Therefore,
passive mass-deposition during CSC through a wire mesh effectively allows to establish a more uniform temporal and radial heat
transfer.
1 Introduction
Superficial vascular lesions, such as hemangiomas and

  

Source: Aguilar, Guillermo - Department of Mechanical Engineering, University of California at Riverside

 

Collections: Engineering