Experimental and numerical study of heat transfer through a synchronous belt transmission type AT10
Highlights • An experimental study on pulley-belt temperature measurement is presented.• The effects of torque, setting tension and angular speed on the belt.• A heat transfer model is proposed to calculate pulley-belt heat flux.• Validation based on experimental thermal surveys and thermocouple measures.• A comparative analysis between two heat fluxes (calculated and simulated) is done.
Investigation of dynamic heat generation and transfer behavior and energy dissipation for nonlinear synchronous belt transmission
Abstract Study on energy dissipation and temperature distribution of synchronous belt transmission is of great importance in industrial engineering field, which is highly related to transmission efficiency estimation, thermal fatigue life prediction, and product design. However, the complex behaviors of viscoelastic hysteresis and meshing friction make it much more difficult to investigate heat generation and transfer mechanism of synchronous belt than other products. To accurately predict temperature and energy dissipation, a thermo-mechanical coupling model was developed through combining experiment and finite element analysis method, in which material nonlinearity of rubber hyper-viscoelasticity, and contact nonlinearity of meshing interference were comprehensively considered. Meanwhile, the friction heat flux partition coefficient and convective heat transfer coefficient were theoretically computed and corrected. As a result, the temperature distribution, hysteresis and friction energy dissipation of synchronous belt could be computed accurately, the transmission efficiency was estimated as well. The simulation temperatures of various operating conditions were confirmed by testing results. The presented methodology can completely predict energy dissipation and temperature distribution of synchronous belt transmission, which has far-reaching consequences in the engineering application filed.
The peculiar thermo-structural behavior of the anionic lipid DMPG.
Aqueous dispersions of the anionic phospholipid dimyristoyl phosphatidylglycerol (DMPG), around 100 mM ionic strength, are known to exhibit a thermal behavior similar to that of the largely studied lipid dimyristoyl phosphatidylcholine (DMPC), which undergoes a gel to liquid crystalline phase transition at 23 degrees C, well characterized by differential scanning calorimetry (DSC), and other methods. However, at low ionic strength, DMPG has been shown to present a large gel-fluid transition region, ranging from 18 to 35 degrees C. This intermediate phase is optically transparent and characterized by a continuous change in membrane packing. Structural properties of the DMPG gel-fluid transition region will be discussed, based on results obtained by several techniques: electron spin resonance (ESR) of spin labels at the membrane surface and intercalated at different depths in the bilayer; light scattering; DSC; small angle X-ray scattering (SAXS); and fluorescence spectroscopy of probes in the bilayer.