Heat Loss in Grooved Metallic Surface

This paper describes an elementary and powerful way to calculate the conduction current losses in metallic waveguide walls, that have parallel periodic grooves of semicircular cross section, when the diameter of the circles is small with respect to the wavelength, but long with respect to the skin depth. The helix circular-electric waveguide falls in this class, and its circular-electricwave losses have been estimated. The method consists in guessing judiciously the solution of Maxwell´s equations close to the wall. It turns out that with the first two obvious guesses, close approximations to the rigorous solution are obtained for grooves at right angles and parallel to the tangential magnetic field.