Transpiration-Cooled Nosetip Development.

Abstract : A 316L stainless steel transpiration-cooled nosetip for a high-performance missile system was designed and fabricated using powder metallurgy techniques. The geometry of the nosetip was established, and permeability requirements were analytically defined. A parametric study of subscale billets determined permeability as a function of powder size and sintering temperature. Near-net-shape billets were fabricated, and machining procedures for the porous material were established. A comparison was made between the actual and calculated gas flow through the nosetip over its entire surface. Two nosetips were successfully tested in a thermal environment approximating the flight environment at the Edward's Air Force Base Rocket Propulsion Laboratory (RPL). Tests were conducted at 0-degree and 10-degree angles of attack. (Author)