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

"The present invention provides a helical formation for a conduit, which can be determined based on the internal dimensions of the conduit, the fluid mass flow, pressure drop, and turbulent kinetic energy. The helix angle can be determined as the angle at which the non-dimensionalised pressure drop and turbulent kinetic energy are substantially equal. The helical formation can be in the form of an insert or an integral part of the conduit. It can effect a rotational flow of fluid within the conduit, reducing turbulence and dead flow regions. The conduit can be used in blood treatment or delivery equipment, industrial equipment, or stent grafts. The flow configuration through the conduit can be measured using magnetic resonance imaging or Doppler ultrasound, and the flow guiding formation can be modified accordingly. The conduit can be flexible or rigid."

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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