Method for determining the angular setting ( β 2) of an annular row of stator vanes arranged downstream of a propeller of a propulsion system having a longitudinal axis, said annular row of stator vanes receiving a flow of air having a speed (V 2) including a longitudinal component (V iz) and a tangential component (V iθ) associated with the speed of gyration generated by the propeller, the method comprising the steps: a) establishing a theoretical model of the propeller using a power (P 1) and a mechanical speed (N 1) associated with said propeller, and the flight conditions comprising a speed of the stream of incident air on the propeller, the altitude of said propulsion system and the ambient temperature; b) determining an angular setting ( β 1) of said propeller from said theoretical model; c) on the basis of said theoretical model of the propeller, defining nondimensionalised parameters including at least a power coefficient (C p,1), a traction coefficient (C T,1) and a ratio of forward movement (J 1) of said propeller defined by the following formulas: C P, 1 = P 1 ρ ⋅ N 1 3 ⋅ D 1 5 C T, 1 = T 1 ρ ⋅ N 1 2 ⋅ D 1 4 J 1 = V 0 N 1 ⋅ D 1 in which ρ corresponds to the density of an ambient air, V 0 corresponds to a flight speed of said propulsion system, N 1 corresponds to said mechanical speed of said propeller, D 1 corresponds to a diameter of said propeller, P 1 corresponds to said power of said propeller, T 1 corresponds to a traction of said propeller; d) calculating the longitudinal component (V iz) and the tangential component (V iθ) of said speed (V 2) of the stream of incident air on said annular row of stator vanes from said nondimensionalised parameters and deducing therefrom an angle ( φ 12) between said speed of the stream of incident air on said annular row of stator vanes and a plane of rotation of said propeller; e) determining an angular setting ( β 2) to be applied to said annular row of stator vanes from said angle ( φ 12), from a Mach number associated with the speed of the stream of incident air on the propeller and from a database associating with each said angle ( φ 12) various angular settings ( β 2) of said annular row of stator vanes obtained for various Mach numbers. a) establishing a theoretical model of the propeller using a power (P 1) and a mechanical speed (N 1) associated with said propeller, and the flight conditions comprising a speed of the stream of incident air on the propeller, the altitude of said propulsion system and the ambient temperature; b) determining an angular setting ( β 1) of said propeller from said theoretical model; c) on the basis of said theoretical model of the propeller, defining nondimensionalised parameters including at least a power coefficient (C p,1), a traction coefficient (C T,1) and a ratio of forward movement (J 1) of said propeller defined by the following formulas: C P, 1 = P 1 ρ ⋅ N 1 3 ⋅ D 1 5 C T, 1 = T 1 ρ ⋅ N 1 2 ⋅ D 1 4 J 1 = V 0 N 1 ⋅ D 1 in which ρ corresponds to the density of an ambient air, V 0 corresponds to a flight speed of said propulsion system, N 1 corresponds to said mechanical speed of said propeller, D 1 corresponds to a diameter of said propeller, P 1 corresponds to said power of said propeller, T 1 corresponds to a traction of said propeller; ρ corresponds to the density of an ambient air, V 0 corresponds to a flight speed of said propulsion system, N 1 corresponds to said mechanical speed of said propeller, D 1 corresponds to a diameter of said propeller, P 1 corresponds to said power of said propeller, T 1 corresponds to a traction of said propeller; d) calculating the longitudinal component (V iz) and the tangential component (V iθ) of said speed (V 2) of the stream of incident air on said annular row of stator vanes from said nondimensionalised parameters and deducing therefrom an angle ( φ 12) between said speed of the stream of incident air on said annular row of stator vanes and a plane of rotation of said propeller; e) determining an angular setting ( β 2) to be applied to said annular row of stator vanes from said angle ( φ 12), from a Mach number associated with the speed of the stream of incident air on the propeller and from a database associating with each said angle ( φ 12) various angular settings ( β 2) of said annular row of stator vanes obtained for various Mach numbers.