Oscillatory Incompressible Fluid Flow in a Tapered Tube With a Free Surface in an Inkjet Print Head

2005 ◽  
Vol 127 (1) ◽  
pp. 98-109 ◽  
Author(s):  
Dong-Youn Shin ◽  
Paul Grassia ◽  
Brian Derby
Keyword(s):  
Fluid Flow ◽  
Free Surface ◽  
Incompressible Fluid ◽  
Numerical Approach ◽  
Computational Time ◽  
Approximate Analytic Solution ◽  
Incompressible Fluid Flow ◽  
Print Head ◽  
Fluid Behavior ◽  
The Cost

Oscillatory incompressible fluid flow with a free surface occurs in an inkjet print head. Due to complex physical fluid behavior, numerical simulations have been a common approach to characterize the pressure and velocity development in time and space. However, the cost of a numerical approach is high in terms of computational time such that approximate analytic approaches have been developed. In this paper, an approximate analytic solution for a tapered nozzle section is described with a proper downstream boundary condition and the physical behavior of the meniscus deformation is modeled with a simple “window” theory.

Incompressible Fluid Flow Through Pipes Packed With Spheres at Low Dimension Ratios

1993 ◽  
Vol 115 (1) ◽  
pp. 169-172 ◽  
Author(s):  
R. M. Fand ◽  
M. Sundaram ◽  
M. Varahasamy
Keyword(s):  
Fluid Flow ◽  
Incompressible Fluid ◽  
Heat Exchangers ◽  
Convection Heat Transfer ◽  
Technical Note ◽  
Incompressible Fluid Flow ◽  
Practical Applications ◽  
Flow Parameters ◽  
Flow Through ◽  
The Cost

This technical note reports the results of the last of a series of three studies of the flow of incompressible fluids through pipes packed with spheres. In the first of these studies, published in the Journal of Fluids Engineering in 1987, it was shown that certain experimentally determined parameters which govern incompressible fluid flow through such packings are substantially independent of the dimension ratio, D/d, for D/d ≥ 40, where D and d represent the pipe and sphere characteristic dimensions (diameters), respectively. The second of the aforementioned studies, published in the Journal of Fluids Engineering in 1990, focused on the range 1.40 ≤ D/d < 40. In this range the flow parameters are functionally dependent upon D/d due to the so-called “wall effect.” The present investigation deals with the range 1.08 ≤ D/d ≤ 1.40, for which it is shown that the results are quite different from those obtained for higher D/d. Correlation equations are presented here by means of which the flow is characterized in the range 1.08 ≤ D/d ≤ 1.40. It is anticipated that this information will have practical applications, such as, for example, calculating the “cost,” in terms of pressure drop, of enhancing the rate of convection heat transfer in heat exchangers by packing the tubes of the heat exchangers with spheres.

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