Semnan University Press Journal of Modeling in Engineering 2008-4854 16 52 2018 03 21 Porous-filled helical double-pipe heat exchanger under asymmetric heat flux Porous-filled helical double-pipe heat exchanger under asymmetric heat flux 409 418 3529 10.22075/jme.2017.6022. FA Maziar Dehghan Nima Tirandaz Mohammad Sadegh Valipour Journal Article 2016 09 04 A helical double-pipe heat exchanger filled with a porous material under asymmetric heat flux is studied analytically. Momentum and energy equations are transformed to the Germano’s coordinate and then expressions representing the velocity and temperature fields are obtained based on the powers of dimensionless curvature using perturbation analysis. To be more insightful, contours of velocity and temperature fields are presented. Results reveal an asymmetric axial velocity profile arising from the curved geometry. The Nusselt number increases with respect to the dimensionless curvature increment as well as the inner to outer radius ratio increase. A helical double-pipe heat exchanger filled with a porous material under asymmetric heat flux is studied analytically. Momentum and energy equations are transformed to the Germano’s coordinate and then expressions representing the velocity and temperature fields are obtained based on the powers of dimensionless curvature using perturbation analysis. To be more insightful, contours of velocity and temperature fields are presented. Results reveal an asymmetric axial velocity profile arising from the curved geometry. The Nusselt number increases with respect to the dimensionless curvature increment as well as the inner to outer radius ratio increase. https://modelling.semnan.ac.ir/article_3529_496f8d3a579516a27b21b9cb3461e750.pdf