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In this study, a diesel engine was used to operate with blends of light fraction waste cooking oil (LFWCO) with diethyl ether (DEE). DEE was blended as an additive in the 5% to 20% ratio in steps of 5% each. The test indicates that LFWCO+15-DEE produced optimum results regarding performance and emission. The BSFC for LFWCO+15-DEE was found to be higher by about 28.9%, and the BTE was lower by about 7.6%, in contrast to diesel, at 100% operating load, respectively. For LFWCO+15-DEE the EGT was lower by about 11.9%, in contrast to neat diesel, at 100% operating load. The various emissions such as carbon monoxide (CO), nitrous oxide (NO), and smoke opacity for LFWCO+15-DEE were found to be lower by about 32.9%, 25%, and 29.4%, but the NO release was more than other blends and it was about 36%, in contrast to diesel at 100% operating load, respectively. [ABSTRACT FROM AUTHOR]

The mathematical modeling of the activation energy and binary chemical reaction system with six distinct types of nanoparticles, along with the magnetohydrodynamic effect, is studied in this paper. Different types of hybrid nanofluids flowing over porous surfaces with heat and mass transfer aspects are examined here. The empirical relations for nanoparticle materials associated with thermophysical properties are expressed as partial differential equations, which are then interpreted into ordinary differential expressions using appropriate variables. The initial shooting method converts the boundary condition into the initial condition with an appropriate guess and finally finds out an accurate numerical solution by using the Runge–Kutta method with numerical stability. Variations in nanoparticle volume fraction at the lower and upper walls of porous surfaces, as well as the heat transfer rate measurements, are computed using the controlling physical factors. The effects of the flow-related variables on the axial velocity, radial velocity, temperature, and concentration profile dispersion are also investigated. The Permeable Reynolds number is directly proportional to the regression parameter. The injection/suction phenomenon associated with the expanding/contracting cases, respectively, have been described with engineering parameters. The hybrid nanoparticle volume fraction (1–5%) has a significant effect on the thermal system and radial velocity. [ABSTRACT FROM AUTHOR]

The numerical analysis of MHD-free convective heat transfer and its interaction with the radiation over a heated flame inside a porous semicircular cavity loaded with SWCNTs–water nanofluid was explored for the very first time in the present work. The two circular arcs of the upper wall of the enclosure were preserved at a constant cold temperature, whereas the middle region of it was considered adiabatic. The midland region of the lower wall was heated partially, while other regions were also assumed adiabatic. An internal hot flame was included inside the cavity, while the cavity was exposed to a magnetic field. The results were illustrated for Hartmann number (0 ≤ Ha ≤ 100), Rayleigh number (104 ≤ Ra ≤ 106), heated region length (0.1 ≤ L ≤ 0.3), solid volumetric fraction (0 ≤ φ ≤ 0.04), Darcy number (10−3 ≤ Da ≤ 10−5) and radiation parameter (0 ≤ Rd ≤ 1). It was found that decreasing L is the best option for enhancing natural convection. Moreover, it was noted that (Nuout) is directly proportion to (Ra), (ϕ), (Rd) and (Da) increase. In contrast, it was in reverse proportion to (Ha). Furthermore, the results showed that augmentation of about (4%) and a decrement of (56.55%) are obtained on the average (Nu) on the heated length by increasing the radiation and the Hartmann number, respectively. Moreover, raising the radiation number from (0 to 1) causes an augmentation of about (73%) in the average (Nu) of the heated flame. Results also indicated that increasing the Hartmann number will cause a decrement of about (82.4%) of the maximum velocity profile in the vertical direction. [ABSTRACT FROM AUTHOR]

In this study, a multi-physics coupled mathematical model was established on thermal stress distribution of double-glazed units with phase-change material (PCM-glazed) for the transient temperature fields and non-uniform intermittent solar irradiation, and the mathematical calculations are in good agreement with the experimental results, which shows that the developed model in present work can solve the coupled thermal stress distribution problem between phase change and intermittent solar irradiation in the PCM-glazed. A case that is the thermal stress distribution on the surface of glazed unit filled with paraffin under the outdoor variable temperature and non-uniform intermittent solar irradiation was studied in autumn in cold region of China. The results show that the stress produced on the surface of glazed unit filled with paraffin varies obvious, PCM layer between the glass panes significantly affects the stress values at different time, which can, respectively, reach up to about 4.59MPa and down to −3.9MPa for tensile and compressive strains once the paraffin in liquid state, due to improved thermal conductivity of PCM throughout phase transition to liquid. Additionally, the frame is the key factor causing temperature gradient of PCM-glazed unit, and the biggest tensile stress appears at the edge. The influence range of the frame on the surface temperature and stress of the PCM-glazed unit is limited and different, and the largest influence distance of the surface temperature and stress from the edge is 0.1 m and 0.03 m, respectively. [ABSTRACT FROM AUTHOR]