Rotational exhaust flow control for diesel exhaust fluid injection

A diesel exhaust fluid (DEF) system, comprising:

• a mixing tube having a mixing tube inlet and a mixing tube outlet,
• wherein a mixture of exhaust and DEF is to flow from the mixing tube inlet to the mixing tube outlet;
• a DEF injector proximate to the mixing tube inlet;
• and
• a flow control device,
• wherein the flow control device includes a plurality of vanes arranged coaxially with the mixing tube,
• wherein a depth of a vane, of the plurality of vanes, is configured to provide a radial-to-axial flow ratio in a target range,
• wherein a ratio of the depth of the vane to a diameter of the mixing tube is in a range of approximately 0.06 to approximately 0.1, and
• wherein the radial-to-axial flow ratio is a particular ratio of radial flow to axial flow for the mixture.

A selective catalytic reduction (SCR) system, comprising:

• an exhaust inlet to receive an exhaust flow;
• a mixing tube, downstream from the exhaust flow, with a mixing tube inlet;
• a diesel exhaust fluid (DEF) injector in the mixing tube to inject DEF for the exhaust flow,
• wherein the mixing tube is to mix the DEF with the exhaust flow;
• and a flow control device proximate to the mixing tube inlet,
• wherein the flow control device is positioned within the mixing tube or affixed to the mixing tube inlet,
• wherein the flow control device includes a plurality of vanes arranged around a center of the flow control device,
• wherein a depth of a vane, of the plurality of vanes, is configured to provide a radial-to-axial flow ratio in a target range, and
• wherein as a ratio of the depth of the vane to a diameter of the mixing tube is in a range of approximately 0.06 to approximately 0.1.