Heat exchanger with expanded metal turbulizer

A heat exchanger, comprising:

• a tubular member having first and second spaced-apart walls defining a fluid flow passage therebetween, the tubular member having a fluid inlet and a fluid outlet, said fluid inlet and fluid outlet being spaced-apart from each other thereby defining a flow direction from the fluid inlet to the fluid outlet for the flow of a first fluid through said fluid flow passage;
• a corrugated heat transfer surface located in said flow passage, the heat transfer surface including parallel spaced-apart ridges with planar portions extending therebetween, alternating ridges being in contact with said first and second spaced apart walls, said corrugated heat transfer surface having a plurality of micro-openings which define porous areas of said corrugated heat transfer surface, said porous areas being located in at least said planar portions, said porous areas having a substantially uniform porosity, and said ridges being oriented perpendicular to the flow direction within said flow passage.