Helical Formation for a Conduit

Abstract

A helical formation within a conduit and a method of determining the helix angle of the helical formation are disclosed. The method includes specifying the internal dimensions of the conduit and an intended fluid mass flow through the conduit. The helix angle is determined from the pressure drop and the turbulent kinetic energy for a conduit having the specified internal dimensions and intended fluid mass flow.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority of U.S. patent application Ser. No. 10 / 516,875, with a U.S. filing date of Dec. 3, 2004. U.S. application Ser. No. 10 / 516,875 is a 371 filing of PCT / GB02 / 05646, filed on Dec. 13, 2002 which in turn claims priority of PCT / GB02 / 02580, filed on Jun. 5, 2002.[0002]Furthermore, the underlying concepts, but not necessarily the language, of U.S. patent application Ser. No. 10 / 516,875 are incorporated herein by reference.[0003]If there are any contradictions or inconsistencies in language between this application and the case that have been incorporated by reference that might affect the interpretation of the claims in this case, the claims in this case should be interpreted to be consistent with the language in this case.FIELD OF INVENTION[0004]The invention relates to a method of determining the helix angle of a helical formation for a conduit, and in particular, but not solely, for blood flow tubing.BACKGROUND ...

AI Technical Summary

Benefits of technology

[0018]The helical formation may effect helical and / or spiral flow in such a fashion as to eliminate or reduce turbulence and / or eliminate or reduce dead flow regions in the conduit. The helix angle to achieve such flow will depend on such factors as diameter of the conduit, longitudinal and rotational velocity of the fluid, and the viscosity and other characteristics of the fluid.

[0020]Alternatively, the conduit may comprise a stent. Stents, for example made of mesh, expanded sheet or tube or wire spring type, are inserted into blood vessels to provide mechanical support and prevent collapse of the blood vessel. A structure according to the present invention could be placed inside or outside the blood vessel to impose, maintain and / or reinforce a flow guiding formation through the blood vessel.

Problems solved by technology

Although the use of helical formations has been proposed as beneficial to fluid flow in conduits by helping to generate spiral fluid flow patterns, there is little or no information on the physical characteristics or design of the helical formation that is required to create a suitable spiral flow pattern.

Clearly, some designs of helical formations will be ineffective at creating spiral flow and others will not create a beneficial spiral flow.

For example, helical formations having a high helix angle may tend to create turbulence rather than spiral flow due.

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