Conditional averaging procedure for the elimination of the small-scale modes from incompressible fluid turbulence at high Reynolds numbers

High-wave-number modes are eliminated in a band characterized by its width parameter in k space. The requisite conditional average is evaluated as an approximation in which coupling effects are neglected to order ^2, for small. A fixed point was found under renormalization-group transformation, which corresponded to the Kolmogorov ``-5/3'' spectrum with spectral constant =1. 60.