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Simulation was employed to estimate the fuel economy enhancement from the application of an exhaust heat recovery system using a thermoelectric generator (TEG) in a series hybrid. The properties of the thermoelectric elements were obtained by self-assessment and set as the conditions for estimating the fuel economy. It was concluded that applying exhaust system insulation and forming the appropriate combination of elements with differing temperature properties inside the TEG could yield an enhancement of about 3% in fuel economy. An actual vehicle was also used to verify the calculation elements in the fuel economy simulation, and their reliability was confirmed.

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Articles you may be interested inUltrathin InAlN/GaN heterostructures on sapphire for high on/off current ratio high electron mobility transistors Effects of In composition on ultraviolet emission efficiency in quaternary InAlGaN light-emitting diodes on freestanding GaN substrates and sapphire substrates Demonstration of an InGaN-based light-emitting diode on an AlN/sapphire template by metalorganic chemical vapor depositionThe authors present a comparison of metal organic chemical vapor deposition grown compositionally graded metamorphic buffers, which enable virtual substrates with very high quality crystal lattices with lattice constants from 5.45 to 5.65 Å ͑threading dislocation density, t , around 10 4 cm −2 ͒. The structures, grown on GaP or GaAs, consist of graded In-fraction InGaP and AlInGaP or graded P-fraction GaAsP. They show that surface roughness and locally strained regions of phase separation ͑branch defects͒ limit misfit dislocation glide velocity and escalate threading dislocation density. High surface roughness and branch defects in ͑Al͒InGaP lead to the lowest quality virtual substrates we observed, with t of around 3 ϫ 10 6 cm −2 . In contrast, graded mixed-anion films of GaAsP avoid branch defects and minimize surface roughness, giving superior defect densities, as low as 10 4 cm −2 at useful lattice constants halfway between that of Si and Ge. Tensile graded GaAs 1−z P z layers yield the smoothest films ͑0.78 nm rms in a 5 m scan͒ with the lowest defect densities but are subject to cracking when graded beyond z = 0.5 with a graded layer thickness of Ͻ10 m. Compressive graded GaAsP yields excellent t values ͑3.3ϫ 10 5 cm −2 ͒ with very thin buffers ͑1.3 m͒. The accelerated grade rate of the compressive buffers increases crosshatch roughness, which along with the higher defect density of GaP substrates, accounts for the higher defect density compared to tensile GaAsP on GaAs substrates.

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