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Body types overview

Parameter value for body_type Description
none (default) No immersed boundary
center_wall Planar static wall centered in y
double_cylinders_z Two concentric cylinders parallel to the z axis
standing_wave Two walls (at y = 0 and y = Ly_ref) undergoing a prescribed streamwise standing wave deformation with the same phase
traveling_wave_x Two walls (at y = 0 and y = Ly_ref) undergoing a prescribed streamwise traveling wave deformation with the opposite phase

Center wall (center_wall)

Field Value
Parameter value for body_type center_wall
nb nxb * nzb
body_param_1 N/A
body_param_2 N/A
body_param_3 N/A
body_ramp_up_time considered? No

Two concentric cylinders parallel to the z axis (double_cylinders_z)

Field Value
Parameter value for body_type double_cylinders_z
nb Computed such that the body-to-grid spacing ratio in the x direction matches that of the z direction, determined by nzb and nz_global
body_param_1 Radius inner cylinder
body_param_2 Radius outer cylinder
body_param_3 Tangential velocity boundary condition at the inner cylinder
body_ramp_up_time considered? No

Streamwise standing wave deformation (standing_wave)

Displacement upper wall:

\[ \eta_{U} = b_1 \cos( b_2 t) \sin( 2 \pi b_3 x / L_{x,p}) \]

Displacement lower wall:

\[ \eta_{L} = b_1 \cos( b_2 t) \sin( 2 \pi b_3 x / L_{x,p}) \]
Field Value
Parameter value for body_type standing_wave
nb 2 * nxb * nzb
body_param_1 (\(b_1\)) Displacement amplitude
body_param_2 (\(b_2\)) Angular frequency
body_param_3 (\(b_3\)) Streamwise mode index
body_ramp_up_time considered? No

Streamwise traveling wave deformations (standing_wave)

Displacement upper wall:

\[ \eta_{U} = -\frac{b_1}{b_2 b_3} \sin( b_3 (x - b_2 t)) \]

Displacement lower wall:

\[ \eta_{L} = \frac{b_1}{b_2 b_3} \sin( b_3 (x - b_2 t)) \]
Field Value
Parameter value for body_type standing_wave
nb 2 * nxb * nzb
body_param_1 (\(b_1\)) Velocity amplitude
body_param_2 (\(b_2\)) Wave speed
body_param_3 (\(b_3\)) Streamwise wavenumber
body_ramp_up_time considered? Yes