Small amplitude kinematic wave propagation in twocomponent media
CaltechAUTHORS
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Title 
Small amplitude kinematic wave propagation in twocomponent media


Creator 
Kytomaa, H. K.
Brennen, C. E. 

Subject 
Caltech Library Services


Description 
The speed and attenuation of small amplitude kinematic waves were measured in vertical bubbly and particulate flows in a continuous medium of water. This was done by evaluating the time delay and phase lag of coherent random fluctuations in the volume fraction signal at two measuring locations. The volume fraction was monitored using two closely spaced Impedance Volume Fraction Meters (Kytomaa (1986)). Using the broadband volume fraction perturbations yields the dependence of the kinematic speed and attenuation of wave number from a single experiment for one set of conditions. The kinematic waves were found to be nondispersive. Bubbly flows are observed to undergo a change in flow regime at an approximate volume fraction of 45%. Prior to onset of churnturbulence, a sharp drop in kenematic wave attenuation is observed above volume fractions of 40%. When further increase in volume fraction is attempted, the homogeneous dispersion suddenly becomes unstable. The particulate flows remain uniformly dispersed for all volume fractions, but above a value of ~55%, the mixture flows like a solid plug. The volume fraction fluctuations become incresingly persistent as the volume fraction approaches the solidification value, but no instability is observed. It is argued that the inability of airwater flows to withstand bubblebubble forces without breakup may account for the differences between the bubbly and particulate flow results.


Date 
1987


Type 
Conference or Workshop Item
PeerReviewed 

Format 
application/pdf


Identifier 
http://authors.library.caltech.edu/120/1/KYT078.pdf
Kytomaa, H. K. and Brennen, C. E. (1987) Small amplitude kinematic wave propagation in twocomponent media. In: 24th ASME/AIChE National Heat Transfer Conference, 1987. http://resolver.caltech.edu/CaltechAUTHORS:KYTnhtc87 <http://resolver.caltech.edu/CaltechAUTHORS:KYTnhtc87> 

Relation 
http://resolver.caltech.edu/CaltechAUTHORS:KYTnhtc87
http://authors.library.caltech.edu/120/ 
