Abstract: The present invention relates to a cooling arrangement in which a fractal passage network is provided incorporating several passage stages. Each passage stage 4, 5, 6, 7 has substantially the same passage cross-section for consistency with other passage stages to facilitate flow pressure control across the fractal passage network. Normally, the length of passages in each passage stage are also specifically determined in order to achieve a consistent flow pressure control. The arrangement is particularly utilised with regard to cooling within turbine engine components such as blade aerofoils.

Abstract: A turbine blade (20) has cooling air passageways (30) and (30a, 30b, 30c.) through the leading edge wall portion (24) which are positionally arranged so as to intersect each other within the wall thickness so as to transmit mechanical stresses into the thicker, non-perforated material of the blade aerofoil (22). Further passageways near the blade root portion (42) do not intersect, the reduced cooling in that area causes expansion and stress absorption.