Novel hot-wire rake design

Over the years several groups have designed rakes to make multipoint hot-wire measurements (Glauser, M.N. (1987) and Bonnet, J. P.(1989)). We have designed a rake that is being used for measurement of instantaneous and long time averaged velocities in turbulent flows. The response characteristics of these wires are similar to those available commercially. The novelty to our design is that the probes are a separate entity from the rake body. This design greatly simplifies the manufacturing process as well as the repair of the wires. The probe bodies are cast from epoxy in an aluminum mold. Gold wires are set into the epoxy body as the prongs for mounting the sensing wire on one end and to couple to the rake body on the other end. The sensing wire used is 5 micron diameter tungsten wire, electoplated with a copper solution to give a sensing length of 1 mm resulting in a 1/d ratio of 200.