A system for heat exchange between a first fluid and a second fluid, the system comprising: a plurality of parting sheets defining a stack of alternating first and second fluid flow conduits (102, 104), each of the first fluid flow conduits configured to conduct therethrough flow of a first fluid from a first input port to a first output port, each of the second fluid flow conduits configured to conduct therethrough flow of a second fluid from a second input port to a second output port, each of the parting sheets defining the first fluid flow conduits including: a plurality of vanes (110, 112), extending: i) along a vane path from a leading edge to a trailing edge; and ii) between first and second parting sheets separating the first fluid flow conduit from first and second adjacent second fluid flow conduits, respectively, wherein the plurality of vanes are separated from one another in a direction transverse to the vane paths thereby defining fluid flow channels therebetween; and a plurality of flow modifiers, each adjacent to a corresponding leading edge of a corresponding one of the plurality of vanes such that the corresponding leading edge is within a disrupted portion of a first fluid flow, wherein each of the plurality of flow modifiers protrudes from at least one of the first and second parting sheets and wherein each of the plurality of flow modifiers does not connect the first and second parting sheets, characterized in that each flow modifier of the plurality of flow modifiers further comprises a profile in cross section of the flow modifier taken through a plane parallel to the parting sheets, wherein the profile is a tear drop profile or an airfoil profile. a plurality of parting sheets defining a stack of alternating first and second fluid flow conduits (102, 104), each of the first fluid flow conduits configured to conduct therethrough flow of a first fluid from a first input port to a first output port, each of the second fluid flow conduits configured to conduct therethrough flow of a second fluid from a second input port to a second output port, each of the parting sheets defining the first fluid flow conduits including: a plurality of vanes (110, 112), extending: i) along a vane path from a leading edge to a trailing edge; and ii) between first and second parting sheets separating the first fluid flow conduit from first and second adjacent second fluid flow conduits, respectively, wherein the plurality of vanes are separated from one another in a direction transverse to the vane paths thereby defining fluid flow channels therebetween; and a plurality of flow modifiers, each adjacent to a corresponding leading edge of a corresponding one of the plurality of vanes such that the corresponding leading edge is within a disrupted portion of a first fluid flow, a plurality of vanes (110, 112), extending: i) along a vane path from a leading edge to a trailing edge; and ii) between first and second parting sheets separating the first fluid flow conduit from first and second adjacent second fluid flow conduits, respectively, i) along a vane path from a leading edge to a trailing edge; and ii) between first and second parting sheets separating the first fluid flow conduit from first and second adjacent second fluid flow conduits, respectively, wherein the plurality of vanes are separated from one another in a direction transverse to the vane paths thereby defining fluid flow channels therebetween; and a plurality of flow modifiers, each adjacent to a corresponding leading edge of a corresponding one of the plurality of vanes such that the corresponding leading edge is within a disrupted portion of a first fluid flow, wherein each of the plurality of flow modifiers protrudes from at least one of the first and second parting sheets and wherein each of the plurality of flow modifiers does not connect the first and second parting sheets, characterized in that each flow modifier of the plurality of flow modifiers further comprises a profile in cross section of the flow modifier taken through a plane parallel to the parting sheets, wherein the profile is a tear drop profile or an airfoil profile.