An exhaust structure includes a piping section, wherein the piping section has a first inner diameter in a central region of the piping section, the piping section has a second diameter in at least one of an inlet or an outlet, and the second diameter has a same value as the first inner diameter. The exhaust structure further includes a plurality of smoothing layers configured to resist turbulence and condensation produced by a flow of one or more gasses in the piping section.