Coanda effect

The Coanda effect refers to the phenomenon by which a narrow jet of liquid (or air) passing through an orifice directly in sequence with a solid (especially convex) surface will deviate from its path and adhere to this curved surface, following its shape in parallel.
Coandă effect influences jet size and color encoding, determining (for eccentric jets) smaller color Doppler jet areas, greater variance and reverse velocity encoding. The phenomenon may alter the interpretation of color Doppler images and needs to be taken into account for an appropriate echocardiography assessment of valvular regurgitation and other abnormal flows.