The invention can be well understood and its advantages appear more clearly on reading the following detailed description of an embodiment given by way of example. The description refers to the accompanying drawings, in which:
The blade 10 shown in
It can be seen that the profile is provided with openings 18 that connect its outside surface to the inside 19 of the profile, which may be hollow, so as to enable it to be cooled by circulating air.
The nominal profile from which the aerodynamic profile of the invention is determined is itself defined in the following table of coordinates, in which the coordinate Z′, taken along the Z axis, is non-dimensional, and thus varies over the range 0 to 1, while the dimensions X and Y measured respectively along the axes X and Y are expressed in millimeters.
In the above table, the plane Z′=0 corresponds to a reference plane P0 situated at the base of the profile, i.e. level with the platform connecting it to the root of the blade.
As mentioned in the beginning of the present description, the aerodynamic profile of the invention is substantially identical to the nominal profile defined in the above table, i.e. it departs at most only very little from the nominal profile, in particular it lies within an envelope of ±1 mm in a direction normal to the surface of the nominal profile, and/or it has X,Y coordinates that lie within a range of ±5% relative to the X,Y coordinates of the nominal profile.
The coordinates in the above table are given from a value Z′=0, i.e. in the reference plane P0. The Z′ coordinate is non-dimensional, i.e. for a point P1 situated at a distance D from the plane P0 (D thus being measured along the Z axis), the value of Z′ is D/H where H represents the total height of the profile, measured from the plane P0 to the tip of the profile. Naturally, multiplying the Z′ coordinate in the above table by the height H gives the full coordinates of the blade.
In the above table, the profile is characterized by 18 sections at constant Z′ coordinate, for which the X and Y coordinates are specified. In each section plane at constant Z′ coordinate, the section of the profile is given by a continuous and smooth curve interconnecting each of the points (X,Y). In each section plane, the profile is interpolated so as to generate a uniform profile.
In
In
The value Emax given in
Preferably, the relationship between the Z′ coordinate and said maximum thickness Emax of the nominal profile complies with the curve of
The variations in the axial chord CA, the area AI, and the maximum thickness Emax given above with reference to the curves of
A turbine blade, in particular for a moving turbine wheel, presenting an aerodynamic profile as defined above with reference to Table 1 and the curves of
It is advantageous for the moving wheel to have 60 to 68 blades, each having an aerodynamic profile in accordance with the invention.
Number | Date | Country | Kind |
---|---|---|---|
0651384 | Apr 2006 | FR | national |