Stenosis ratio SR = 1 − D
s
/D
n
0.70
Flow rate Q (L/min)
5.0
Loss coefficient K
t
1.52
Young–Tsai pressure drop across an axisymmetric stenosis (Yuhn 2022 Eq 4, as implemented in
aortacfdx/onedim/stenosis.py
): ΔP = R
v
Q + K
t
(8ρ/π²D
n
⁴)(1/(1−SR)² − 1)² Q|Q| + K
u
(4ρL
s
/πD
n
²) dQ/dt. Steady flow shown; the unsteady K
u
term vanishes here.