Water and Forced-Air Cooling of Vacuum Tubes Nonelectronic Problems in Electronic Tubes

General laws of heat transfer from a hot wall to a moving fluid are applied to water and forced-air cooling of vacuum tubes. The calculated data are compared with experimental results. The practical importance of various factors constituting the mechanism of heat transfer is analyzed; the role of the internal structure of the tube on the dissipation limits is discussed generally. Rules for designing finned air coolers are outlined, and the "optimum" design is discussed. Numerical examples are given. Some limiting factors in cooler design are analyzed.