Estimating flow rates in open-channel geometries having capillary pumping vanes
AssigneeInternational Business Machines Corporation
InventorRadhakrishnan Srinivasan
Life of this patent
Estimating the term…
Abstract
A method of estimating liquid flow rates in capillary structures has application in determining the surface tension-driven flow rates of liquid fuel in propellant management devices in zero-gravity conditions. Analytic equations governing an assumed open-channel geometry are simplified by reasonable approximations, which allow a modified set of analytic equations to be derived. This modified set of analytic equations is derived by assuming an artificial taper in the capillary passage. Flow rate can be determined from the modified set of equations, which closely approximates the flow rate in the open-channel geometry.
Claims32
A method of estimating the flow rate of a liquid through an open-channel geometry, the method comprising steps of:
- defining (i) an open-channel geometry having an inlet end and an outlet end, between which there is a capillary passage having two parallel walls, (ii) a set of parameters associated with the open-channel geometry, and (iii) analytical equations involving the set of parameters which govern the flow of liquid through the open-channel geometry;
- and
- deriving a modified set of analytic equations corresponding to the governing analytic equations of the open-channel geometry, and solving said modified set of analytic equations to calculate a representative flow rate defined by the modified set of equations;
- wherein said modified set of equations are derived from a modified open-channel geometry based on an artificial assumption that an elongate dimension of the open-channel geometry is tapered, so that the representative flow rate can be calculated as an approximation of the flow rate in the open-channel geometry.
An apparatus for estimating the flow rate of a liquid through an open-channel geometry, the apparatus comprising:
- means for defining (i) an open-channel geometry having an inlet end and an outlet end, between which there is a capillary passage having two parallel walls, (ii) a set of parameters associated with the open-channel geometry, and (iii) analytical equations involving the set of parameters which govern the flow of liquid through the open-channel geometry;
- and
- means for deriving a modified set of analytic equations corresponding to the governing analytic equations of the open-channel geometry, and solving said modified set of analytic equations to calculate a representative flow rate defined by the modified set of equations;
- wherein said modified set of equations are derived from a modified open-channel geometry based on an artificial assumption that an elongate dimension of the open-channel geometry is tapered, so that the representative flow rate can be calculated as an approximation of the flow rate in the open-channel geometry.
A computer program product having a computer readable medium having a computer program recorded therein for estimating the flow rate of a liquid through an open-channel geometry, said computer program comprising:
- code means for recording a definition of (i) an open-channel geometry having an inlet end and an outlet end, between which there is a capillary passage having two parallel walls, (ii) a set of parameters associated with the open-channel geometry, and (iii) analytical equations involving the set of parameters which govern the flow of liquid through the open-channel geometry;
- and
- code means for storing a modified set of analytic equations corresponding to the governing analytic equations of the open-channel geometry, and solving said modified set of analytic equations to calculate a representative flow rate defined by the modified set of equations;
- wherein said modified set of equations are derived from a modified open-channel geometry based on an artificial assumption that an elongate dimension of the open-channel geometry is tapered, so that the representative flow rate can be calculated as an approximation of the flow rate in the open-channel geometry.
Dependencies are inferred from the claim text.