  The acoustic radiation force produced by ultrasonic waves is the "workhorse"
of particle manipulation in acoustofluidics. Nonspherical particles are also
subjected to a mean torque known as the acoustic radiation torque. Together
they constitute the mean-acoustic fields exerted on the particle. Analytical
methods alone cannot calculate these fields on arbitrarily shaped particles in
actual fluids and no longer fit for purpose. Here, a semi-analytical approach
is introduced for handling subwavelength axisymmetric particles immersed in an
isotropic Newtonian fluid. The obtained mean-acoustic fields depend on the
scattering coefficients that reflect the monopole and dipole modes. These
coefficients are determined by numerically solving the scattering problem. Our
method is benchmarked by comparison with the exact result for a subwavelength
rigid sphere in water. Besides, a more realistic case of a red blood cell
immersed in blood plasma under a standing ultrasonic wave is investigated with
our methodology.
