In accordance with an embodiment, a shockwave device (100, 200) suitable for thermally heating a process fluid is disclosed, the shockwave device comprising an axially oriented inlet (101, 201) and outlet (102, 202) defining an axially enclosed volume along an axis, the device having a stage between the inlet (101, 201) and outlet (102, 202), the stage comprising: a first rotor (104, 206) comprising a first set of blades, the first set of blades comprising a second set of blades, a first set of blades distributed about the axis and configured to rotate in a first rotational direction; a second rotor (105, 207) comprising a second set of blades distributed about the axis and configured to rotate in a second direction of rotation opposite the first direction of rotation; no blade space exists; and whereby the stage is configured to force the process fluid to flow from the inlet (101, 201) to the outlet (102, 202) by rotating the first rotor (104, 206) and the second rotor (105, 207).