Abstract: A steel piston for coupling to a connecting rod and wrist pin is provided. The piston includes a body with an upper crown presenting a combustion surface for exposure to a combustion chamber. The upper crown presents an undercrown surface which is openly exposed as viewed from an underside of the piston and not bounded by a cooling gallery. The body includes a ring belt and pin bosses depending from the ring belt and presenting a pin bore for receiving the wrist pin. The body also includes ribs disposed along the undercrown surface. The body includes a ratio of compression height to outer diameter (CH/D) ranging from 34.8% to 42.0%. The piston also includes a low heat transfer coating on the combustion surface, and the low heat transfer coating has a thermal conductivity of about 0.20 to 0.80 W/m·K.

Abstract: A steel piston for coupling to a connecting rod and wrist pin is provided. The piston includes a body with an upper crown presenting a combustion surface for exposure to a combustion chamber. The upper crown presents an undercrown surface which is openly exposed as viewed from an underside of the piston and not bounded by a cooling gallery. The body includes a ring belt and pin bosses depending from the ring belt and presenting a pin bore for receiving the wrist pin. The body also includes ribs disposed along the undercrown surface. The body includes a ratio of compression height to outer diameter (CH/D) ranging from 34.8% to 42.0%. The piston also includes a low heat transfer coating on the combustion surface, and the low heat transfer coating has a thermal conductivity of about 0.20 to 0.80 W/m·K.

Abstract: A fluid detector and a method of detecting a fluid are described. The fluid detector includes a broadband light source (10) for providing a light beam (12) including light of at least a predetermined bandwidth, and an optical power detector (40) arranged to provide an output signal indicative of the total power of incident light. An optical path extends from the light source to the optical power detector. The optical path includes a tunable optical filter (20) and a fluid sampling region (30). The tunable optical filter is a tunable optical band-rejection filter, and has a rejection band narrower than the bandwidth of the light beam. The rejection band is swept across the wavelengths of the predetermined bandwidth of the light beam. The tunable optical filter may comprise a fiber Bragg grating.