  Acoustic spin, radiation torque, energy flow, and reactive power are of
significant importance from both fundamental and practical aspects, responsible
for flexible tweezer manipulations and near-field sound directionality.
Nevertheless, the intrinsic relations among these physical quantities are far
from clear. Here, we prove the universal geometric relations among them in
acoustics, independent on wave structure details. Particularly, we connect
acoustic spin and torque to the cross product of time-averaged energy flow and
reactive power, as well as to the local vorticity of energy flow. These
relations are universally valid, verified in a variety of different acoustic
systems. We also demonstrate the multipole mechanical torques and forces
generated in three acoustic near-field sources: Janus, Huygens and Spin
sources, applying on small lossy particles. These universal geometric relations
uncover hidden locking relations beyond simple spin-momentum locking of
near-field waves, and show the basic principles between the acoustic spin,
radiation torque, and energy flow, reactive power.
