A Numerical Investigation of Unsteady Bubbly Cavitating Nozzle Flows
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Title 
A Numerical Investigation of Unsteady Bubbly Cavitating Nozzle Flows


Creator 
Preston, A. T.
Colonius, T. Brennen, C. E. 

Subject 
Caltech Library Services


Description 
The effects of unsteady bubbly dynamics on cavitating flow through a convergingdiverging nozzle are investigated numerically. A continuum model that couples the RayleighPlesset equation with the continuity and momentum equations is used to formulate unsteady, quasionedimensional partial differential equations. Flow regimes studied include those where steadystate solutions exist, and those where steadystate solutions diverge at the socalled flashing instability. these latter flows consist of unsteady bubbly shock waves traveling downstream in the diverging section of the nozzle. An approximate analytical expression is developed to predict the critical backpressure for choked flow. The results agree with previous barotropic models for those flows where bubbly dynamics are not important, but show that in many instances the neglect of bubbly dynamics cannot be justified. Finally the computations show reasonable agreement with an experiment that measures the spatial variation of pressure, velocity and void fraction for steady shockfree flows, and good agreement with an experiment that measures the throat pressure and shock position for flows with bubbly shocks. In the model, damping of the bubbly raidal motion is restricted to a simple "effective" viscosity, but many features of the flow are shown to be independent of the specific damping mechanism.


Date 
200201


Type 
Article
PeerReviewed 

Format 
application/pdf


Identifier 
http://authors.library.caltech.edu/138/1/PRE206.pdf
Preston, A. T. and Colonius, T. and Brennen, C. E. (2002) A Numerical Investigation of Unsteady Bubbly Cavitating Nozzle Flows. Physics of Fluids, 14 (1). pp. 300311. ISSN 10706631. http://resolver.caltech.edu/CaltechAUTHORS:PREpf02 <http://resolver.caltech.edu/CaltechAUTHORS:PREpf02> 

Relation 
http://resolver.caltech.edu/CaltechAUTHORS:PREpf02
http://authors.library.caltech.edu/138/ 
