Radiatore gets its name from the little radiators they were patterned after, as legend has it sometime between the 1920s and 1940s. The open center and large surface area hold thick sauces well, and the ruffled edges trap savory bits of meaty ragus, from lamb to veal to rabbit or pork. Just as radiators maximize surface area to exchange heat, radiatore use that feature to absorb flavors. The dense structure also makes them a good choice for cold pasta salads, as they retain al dente bite well.
The Pasta Encyclopedia: Radiatore