Circular flow number of generalized Blanuša snarks

A circular flow   on a graph is an assignment of directions and flow values from RR to the edges so that for each vertex the sum of the flow values on exiting edges equals the sum of the flow values on entering edges. A circular nowhere-zero  rr-flow   is a circular flow ϕϕ with flow values satisfying 1≤|ϕ(e)|≤r−11≤|ϕ(e)|≤r−1 for each edge ee. The circular flow number   of a graph GG is the infimum of all reals rr such that GG has a circular nowhere-zero rr-flow. We prove that the circular flow number of all generalized Blanuša snarks except for the Petersen graph is 4.5. We also bound the circular flow number of Goldberg snarks, both from above and from below.