A flow device, includes a flow-through region comprising at least one stage and configured to create a first pressure drop across the flow-through region in response to flow through the flow-through region in a first direction and a second pressure drop in response to flow through the flow-through region in a second direction. The first pressure drop being less than the second pressure drop under the same flow rates. The flow device having no moving parts to create the difference in pressure drop between the first direction and the second direction. A method of creating different pressure drops based on a direction of flow.