Viscous damping and effective helical ripple have been quantitatively estimated for a proposed quasi-axisymmetric stellarator CHS-qa configuration.It is predicted that viscous damping against plasma flow in CHS-qa is low enough to sustain large E×B shear as observed in the H-modesand internal transport barriers in many tokamaks. Effective helical ripple in CHS-qa is adjusted to be on the order of 10-2 or lower,which is suitable to trigger transport barriersdue to non-ambipolar neoclassical fluxes peculiar to conventional helical devices.For experimental flexibility, viscous damping and effective helical ripple in CHS-qacan be extensively controlled over a range of about one order by modifying modular coil currents.