Abstract: A fluid flow modification apparatus has a plurality of flow modification elements each having a first surface portion against which a fluid (F) can flow and a second surface portion along which the fluid (F) can flow. The elements are arranged in a number of sets. A first set of elements comprises a plurality of fluid flow modification elements with a first surface portion. A second set of elements comprises a plurality of fluid flow modification elements with a first surface portion having a surface area different from that of the first set. The first set of elements includes first and second types of fluid flow modification elements. The depth of the second surface portion is different from the depth of the second surface portion.

Abstract: A turbulence-generating grid for producing a turbulent flow is provided. The grid has a top and a bottom and opposed sides and comprises a number N of layers, each layer being defined between respective pairs of horizontal bars and the sides of the grid. Each layer is subdivided by a number cn of vertical bars so as to define a plurality of respective through holes between at least adjacent pairs of the vertical bars and the horizontal bars. At least one of the dimensions and the spacings of the vertical bars of one of the layers is different from the at least one of the dimensions and the spacings of the vertical bars of another of the layers.

Abstract: A fluid flow modification apparatus has a plurality of flow modification elements each having a first surface portion against which a fluid (F) can flow and a second surface portion along which the fluid (F) can flow. The elements are arranged in a number of sets. A first set of elements comprises a plurality of fluid flow modification elements with a first surface portion. A second set of elements comprises a plurality of fluid flow modification elements with a first surface portion having a surface area different from that of the first set. The first set of elements includes first and second types of fluid flow modification elements. The depth of the second surface portion is different from the depth of the second surface portion.

Abstract: A fluid flow modification apparatus (10) has a surface (15), the surface having an edge (65) of length Y over or past which a fluid can flow in use. The edge (65) has a virtual boundary (30) of length X where Y is greater than X. At least a first portion of the apparatus (10) within the virtual boundary (30) comprises an opening (55) and at least a second portion of the apparatus (10) comprises a projection (60) which extends beyond the virtual boundary (30) to provide the edge (65). The edge (65) is multi-scale.

Abstract: A fluid flow modification apparatus for creating turbulence in a moving fluid includes turbulence-creating elements arranged in a fractal configuration, each element having a first surface portion against which the fluid can flow and a second surface portion along which the fluid can flow, and further includes an insert for arrangement to obstruct the flow of fluid between adjacent second surface portions of at least two turbulence-creating elements. A support holds the turbulence-creating elements in the fluid to allow movement of the fluid relative to the turbulence-creating elements and the insert. The insert may be attachable to at least two turbulence-creating elements, such that the arrangement of the inserts is symmetrical about a centre point of the fluid flow field for improved mixing.

Abstract: Embodiments of the invention relate to apparatus for modifying the properties of a flow field and to a method of selecting an apparatus to achieve a desired flow field. The invention finds particular application in the control of the mixing of fluids, heat transfer within and between fluids, acoustic noise, oscillations in fluids, microchip cooling, structural vibrations and chemical reactions.