  Yield stress materials form an interesting class of materials that behave
like solids at small stresses, but start to flow once a critical stress is
exceeded. It has already been reported both in experimental and simulation work
that flow curves of different yield stress materials can be scaled with the
distance to jamming or with the confining pressure. However, different scaling
exponents are found between experiments and simulations. In this paper we
identify sources of this discrepancy. We numerically relate the volume fraction
with the confining pressure and discuss the similarities and differences
between rotational and oscillatory measurements. Whereas simulations are
performed in the elastic response regime close to the jamming transition and
with very small amplitudes to calculate the scaling exponents, these conditions
are hardly possible to achieve experimentally. Measurements are often performed
far away from the critical volume fraction and at large amplitudes. We show
that these differences are the underlying reason for the different exponents
for rescaling flow curves.
