Asymmetric heating effect on heat transfer and carbon depositions of pyrolytic hydrocarbon fuel in curved cooling channels.

• Heat transfer and carbon depositions in asymmetrically heated curved channels were analyzed. • Secondary flow reduced the non-uniformities of the fuel temperature and conversion. • Stronger secondary flow resulted in lower heated wall temperature and carbon deposition. • The decreasing radius of curvature enhanced asymmetric heating effect on heat and mass transfer. Numerical study was carried out to investigate the effect of asymmetric heating on fuel pyrolysis, heat transfer and carbon depositions in curved cooling channels around the cavity flame-holder. The results reveal that the secondary flow velocity determines the flow structure, heat transfer and carbon depositions in asymmetrically heated curved cooling channels. In the concave heated case, the drastic variations of the radial pressure gradient with fuel pyrolysis induce higher secondary flow velocity, which is of benefit to the utilization of fuel heat absorption capacity and the inhibition of carbon deposition. Under the asymmetric heating and secondary flow effects, compared with the convex heated case, the heated wall HTC rises, while the heated wall temperature and the total carbon depositions drop in the concave heated case. In addition, the increasing radius of curvature reduces the asymmetric heating effect on heat transfer and carbon depositions in the curved cooling channel. [ABSTRACT FROM AUTHOR]