Accession Number:

ADA021130

Title:

A Laser Diagnostic Technique for the Measurement of Droplet and Particle Size Distributions,

Descriptive Note:

Corporate Author:

SHEFFIELD UNIV (ENGLAND) DEPT OF CHEMICAL ENGINEERING AND FUEL TECHNOLOGY

Personal Author(s):

• Swithenbank,J.
• Beer,J. M.
• Taylor,D. S.
• Abbott,D.
• McCreath,G. C.

Report Date:

1975-12-01

Pagination or Media Count:

14.0

Abstract:

In order to verify the various theoretical models of practical combustion systems, experimental measurements are urgently required. A number of laser instrumentation systems which do not disturb the flow are being devised to satisfy this need. This study describes a technique which has been developed for the measurement of droplet or solid particle size distribution. These measurements are required, for example, as the input to mathematical models of combustion which include evaporation. The technique is based on the Fraunhofer diffraction of a parallel beam of mono-chromatic light by the moving droplets. A Fourier transform lens is used to focus a stationary light pattern onto a multielement photo-detector to measure the diffracted light energy distribution. A mini-computer program translates the light energy distribution into the corresponding, unique, droplet size distribution. The droplets or particles are classified into 31 size groups spanning two decades of diameter, e.g. 5 micrometers to 500 micrometers using a 300 mm focal length Fourier transform lens.

Descriptors:

• *TEST EQUIPMENT
• *COMBUSTION
• PARTICLE SIZE
• LASER BEAMS
• MEASURING INSTRUMENTS
• DROPS
• INSTRUMENTATION
• FUEL SPRAYS
• EVAPORATION
• FUEL INJECTION
• COMBUSTION PRODUCTS
• UNITED KINGDOM

Subject Categories:

• Test Facilities, Equipment and Methods
• Optics
• Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE