  We analyse velocity fluctuations in the solar wind at magneto-fluid scales in
two datasets, extracted from Wind data in the period 2005-2015, that are
characterised by strong or weak expansion. Expansion affects measurements of
anisotropy because it breaks axisymmetry around the mean magnetic field.
Indeed, the small-scale three-dimensional local anisotropy of magnetic
fluctuations ({\delta}B) as measured by structure functions (SF_B) is
consistent with tube-like structures for strong expansion. When passing to weak
expansion, structures become ribbon-like because of the flattening of SFB along
one of the two perpendicular directions. The power-law index that is consistent
with a spectral slope -5/3 for strong expansion now becomes closer to -3/2.
This index is also characteristic of velocity fluctuations in the solar wind.
We study velocity fluctuations ({\delta}V) to understand if the anisotropy of
their structure functions (SF_V ) also changes with the strength of expansion
and if the difference with the magnetic spectral index is washed out once
anisotropy is accounted for. We find that SF_V is generally flatter than SF_B.
When expansion passes from strong to weak, a further flattening of the
perpendicular SF_V occurs and the small-scale anisotropy switches from
tube-like to ribbon-like structures. These two types of anisotropy, common to
SF_V and SF_B, are associated to distinct large-scale variance anisotropies of
{\delta}B in the strong- and weak-expansion datasets. We conclude that SF_V
shows anisotropic three-dimensional scaling similar to SF_B, with however
systematic flatter scalings, reflecting the difference between global spectral
slopes.
