Numerical study on flow field and separation performance of swirl-vane separator under rolling motion conditions

Swirl-vane separator is essential in marine nuclear SG for separating liquid droplets from gas flow. This study conducts 3D numerical simulations to investigate the impact of rolling amplitude (theta(m)) and rolling period (T) on flow field and separation performance under rolling motion, incorporating additional inertia forces through a UDF. Results indicate that non-axisymmetric patterns in vapor velocity and total pressure fields exhibit periodic fluctuations, lagging approximately one-quarter period behind the separator's movement due to inertia forces. The fluctuation of liquid volume fraction resembles a sinusoidal periodic pattern. Separation efficiency fluctuates in an "M" pattern within 10 degrees < theta(m) < 40 degrees and 4 s < T < 8 s, and in a "W" at theta(m) = 40 degrees and 30 degrees, with T = 2 s. Pressure loss fluctuation follows a "W" pattern. Increasing rolling amplitude and decreasing period intensify liquid film thickness variability near separator walls, reducing separation efficiency, increasing pressure loss.