FLOW OF LIQUID FILM ALONG CYLINDRICAL SURFACE. Part I. Theoretical Considerations

This paper presents a method of producing charged droplets using standing capillary waves in a thin liquid film on a vibrating surface. Capillary waves with wavelengths on the order of microns are set to reach a critical stable condition and an electric field is applied to extract charged droplets from the crest of unstable waves. This method is more efficient than the method based on stable Taylor cones working in the cone-jet mode in producing a large quantity of uniformly charged droplets. Theoretical analyses on the droplet diameter, charge-to-mass ratio and the total current emitted from capillary waves are also presented.

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Sub-delta volume generation for recognition of freeform cylindrical surface part model

Journal of Physics Conference Series ◽

10.1088/1742-6596/1150/1/012007 ◽

2019 ◽

Vol 1150 ◽

pp. 012007

Author(s):

Ahmad Faiz Zubair ◽

Mohd Salman Abu Mansor

Keyword(s):

Cylindrical Surface ◽

Surface Part ◽

Part Model

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Theoretical considerations concerning the profile error of the thread flank

MATEC Web of Conferences ◽

10.1051/matecconf/201817801006 ◽

2018 ◽

Vol 178 ◽

pp. 01006

Author(s):

Laurenţiu Slătineanu ◽

Oana Dodun ◽

Irina Beşliu Băncescu ◽

Ionel Coman ◽

Adrian Ghionea ◽

...

Keyword(s):

Analytical Method ◽

Cylindrical Surface ◽

Cutting Tool ◽

Simplified Model ◽

External Diameter ◽

Profile Error ◽

Tool Edge ◽

Theoretical Considerations ◽

The Way

In the case of metric thread, a possible source of the flank error could be the position of the cutting tool edge, which could not intersect the circular cylindrical surface axis. An analytical method of approximation was applied to model the way in which the flank error is generated by considering some geometrical conditions. A theoretical simplified model was determined to highlight the influence of the thread external diameter and of the distance between the circular cylindrical surface axis and the thread rectilinear generatrix on the profile error of thread flank.

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Velocity Distribution in the Liquid Film During Draining on a Cylindrical Surface

Journal of Applied Mechanics ◽

10.1115/1.3408956 ◽

1971 ◽

Vol 38 (4) ◽

pp. 795-797

Author(s):

T. C. Chawla ◽

H. K. Fauske

Keyword(s):

Liquid Film ◽

Velocity Distribution ◽

Cylindrical Surface ◽

Initial Period ◽

Vertical Plane ◽

Steady State Solution ◽

Hankel Transform ◽

Momentum Equation ◽

Creeping Flow ◽

Finite Hankel Transform

The solution of the momentum equation describing unsteady creeping flow of the liquid film during its initial period of drainage on a cylindrical surface has been obtained by the method of finite Hankel transform. The steady-state solution describing the later stages of the drainage process [1, 2] has been deduced by letting the time since the start of motion to be infinite. For completeness, the derivation of the velocity distribution for the vertical plane case applying finite sine transform (equivalent of finite Hankel transform for a cylindrical surface) has also been included.

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SUBSTITUTION OF NTO BY HTP IN A BIPROPELLANT RCS

Revista de Engenharia Térmica ◽

10.5380/ret.v2i2.3478 ◽

2003 ◽

Vol 2 (2) ◽

Author(s):

U. C. Oliveira ◽

D. J. F. Villas Bôas

Keyword(s):

Control System ◽

Liquid Film ◽

Film Cooling ◽

Preliminary Analysis ◽

Thermal Environment ◽

Significant Modification ◽

Roll Control ◽

Operational Temperature ◽

Chamber Temperature ◽

Theoretical Considerations

The present article presents some theoretical considerations about the implications due the change of the oxidizer in a bipropellant propulsion system. Preliminary analysis conducted on the NTO/UDMH 400 N engine of a roll control system shows that this engine could be capable of operation with HTP90 without significant modification in the design. The new propellant combination is less toxic, can be handled more easily, has a wider operational temperature range, and yields a more amenable thermal environment from the combustion down to the exhaustion. Even with a decrease in liquid film cooling, the HTP90/UDMH engine would present a satisfactory reduction of the combustion chamber temperature and approximately the same performance level of the original NTO/UDMH engine.

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