S-stable foliations on flow-spines with transverse reeb flow

The notion of S-stability of foliations on branched simple polyhedrons is introduced by R. Benedetti and C. Petronio in the study of characteristic foliations of contact structures on 3-manifolds. We additionally assume that the 1-form b defining a foliation on a branched simple polyhedron P satisfies db > 0, which means that the foliation is possibly a characteristic foliation of a contact form whose Reeb flow is transverse to P. In this paper, we show that if there exists a 1-form b on P with db > 0 then we can find a 1-form with the same property and additionally being S-stable. We then prove that the number of simple tangency points of an S-stable foliation on a positive or negative flow-spine is at least 2 and give a recipe for constructing a characteristic foliation of a 1-form b with db > 0 on the abalone.