摘要:
A curved turbulator configuration is in a radial cooling passage of an airfoil, where the radial cooling passage is defined by at least a leading wall and a trailing wall, and the airfoil includes a tip and a root. The curved turbulator configuration includes a number of spaced curved turbulator pairs positioned along a center-line on an inner surface of the leading wall and a number of spaced complementary curved turbulator pairs positioned along a center-line on an inner surface of the trailing wall. An electrode for forming the curved turbulator configuration in the radial cooling passage includes a leading face having a curved turbulator pattern, a trailing face having a complementary curved turbulator pattern, a conductive core, and an insulating coating disposed thereon that is partly removed.
摘要:
The back side recessed cooling surface of a shroud defining in part the hot gas path of a turbine is electrochemically machined to provide surface roughness elements and spaces therebetween to increase the heat transfer coefficient. To accomplish this, an electrode with insulating dielectric portions and non-insulating portions is disposed in opposition to the cooling surface. By passing an electrolyte between the cooling surface and electrode and applying an electrical current between the electrode and a shroud, roughness elements and spaces therebetween are formed in the cooling surface in opposition to the insulating and non-insulating portions of the electrode, hence increasing the surface area and heat transfer coefficient of the shroud.
摘要:
An electrode for rejuvenating a cooling passage within an airfoil, the electrode including a tip, an end, a conductive core extending between the tip and the end, and an insulating coating disposed on the conductive core. The insulating coating exposes a number of conductive strips of the conductive core extending between the tip and the end. The insulating coating forms a number of insulating portions and further exposes a number of spacer portions of the conductive core longitudinally positioned between the insulating portions. The insulating portions substantially span a distance between the tip and the end and are positioned between the conductive strips.
摘要:
An electrode having a dielectric coating is patterned to provide axially spaced rows of insulating material on the external surface of the electrode with one or more gaps in the insulating material of each row. The electrode is placed in a preformed hole of a turbine bucket and an electrolyte is provided for flow between the electrode and the walls of the hole. Upon application of an electrical current, portions of the material of the interior wall surface directly opposite the non-insulated portions of the electrode are dissolved, forming grooves. The insulated portions of the electrode leave axially spaced rows of projections extending toward the axis of the hole. The gaps in the rows or projections are axially misaligned. The projections form turbulators in the cooling flow passages of the bucket, enhancing the heat transfer coefficient.
摘要:
A machining process for forming a raised area in a wall of a predrilled hole includes distributing electrolyte via a workpiece internal cavity to a number of predrilled holes. Next, position a template including at least one electrode coated with an insulating material in a pattern defining the raised area to be formed in the wall of the predrilled hole below the workpiece such that the electrode is positioned within a predrilled hole and machining by passing electric current between the electrode and the workpiece wall and circulating electrolyte through the hole.
摘要:
An electrode used as a tool in an electrochemical machining process to generate raised areas or ridges in the walls of a predrilled hole in an electrically conductive workpiece has an electrically conductive cylinder partially coated with an electrically insulating material in a pattern defining the raised areas to be formed. The pattern may comprise a plurality of spaced apart rings. An electrochemical machining method of drilling bulbs in the walls of a predrilled hole uses the electrode of the invention to greatly increase process efficiency.
摘要:
An electrode used as a tool in an electrochemical machining process to generate raised areas or ridges in the walls of a predrilled hole in an electrically conductive workpiece has an electrically conductive cylinder partially coated with an electrically insulating material in a pattern defining the raised areas to be formed. The pattern may comprise a plurality of spaced apart rings. An electrochemical machining method of drilling bulbs in the walls of a predrilled hole uses the electrode of the invention to greatly increase process efficiency.
摘要:
An electrochemical machine is disclosed for use in an electrochemical machining process to simultaneously generate different levels of metal removal. The electrochemical machine comprises at least two electrodes, each including an electrically conductive cylinder having an external surface partially coated with an insulated coating. The insulating coating is in a pattern defining raised areas to be formed on an internal surface of a predrilled hole in a workpiece wherein at least one of the electrodes has a varied pattern of insulating coating.
摘要:
An electrode for use in an electrochemical machining process comprising an outer metal skin of corrosion resistant material, an inner core of conductive material, and an insulating coating disposed on an external surface of the outer metal skin. The external surface is partially coated with the insulating coating so as to define a pattern of raised areas to be formed on an internal surface of a predrilled hole in a workpiece.
摘要:
A method for forming holes in an object is provided. The method includes providing an electrochemical machining (ECM) electrode including a first section having insulation that circumscribes the first section, and a second section having insulation that extends only partially around the second section. The method also includes inserting the electrode into the object, such that in a single pass the electrode forms a hole that includes a first portion having a first cross-sectional area and a second portion having a second cross-sectional area.