Design and performance analysis of dual vibrating motors self synchronous shaker with balanced elliptical motion

According to the basic principle of machine dynamics, the mechanical model of the dual vibrating motors self synchronous shaker with balanced elliptical motion is established. By virtual prototype technology, the kinematic and dynamic characteristic simulation analysis of the sieving box was carried out. The motion path, natural frequencies and mode shapes of the sieving box were calculated, the stress and deformation distribution in every part of the sieving box under rate load were obtained, and the dynamic strength analysis of the sieving box was carried out. The results show that, the structure design of the shaker is reasonable, and its dynamic strength is satisfied

The Effect of Normal Force on the Coupled Temperature Field of Metal Impregnation Carbon/Stainless Steel under the Friction and Wear with Electric Current

AbstractTemperature field model for aluminum-stainless steel composite conductor rail (stainless steel)/collector shoe (metal impregnation carbon) under the coupling of contact resistor-friction thermal was established by FE software ANSYS. The temperature field distribution model of the friction pair was simulated and the maximum coupled temperature changing with different normal force was researched. The results show that the maximum coupled temperatures decrease firstly and then rise with the increasing of normal force under the constant displacement, current and relative sliding speed. There is an optimal normal force making the maximum coupled temperature to be the lowest for the friction pair of the metal impregnation carbon and stainless steel. The normal force can be used as the working normal force in order to reduce the abrasion induced by temperature rising

Design and performance analysis of dual vibrating motors self synchronous shaker with balanced elliptical motion

According to the basic principle of machine dynamics, the mechanical model of the dual vibrating motors self synchronous shaker with balanced elliptical motion is established. By virtual prototype technology, the kinematic and dynamic characteristic simulation analysis of the sieving box was carried out. The motion path, natural frequencies and mode shapes of the sieving box were calculated, the stress and deformation distribution in every part of the sieving box under rate load were obtained, and the dynamic strength analysis of the sieving box was carried out. The results show that, the structure design of the shaker is reasonable, and its dynamic strength is satisfied

Research on the Reciprocating Sealing of Fracturing Pump

The failure reasons of reciprocating sealing in OPI-1800AWS fracturing pump is analyzed by scanning electron microscope technology (SEMT). The lubrication mechanism of plunger seal friction pair is analyzed by hydrodynamic lubrication theory. During its discharge and suction stroke, the reciprocating sealing friction pair meets the conditions of hydrodynamic lubrication, a certain thickness of oil film can be formed and maintained between the plunger and V-shaped sealing interface, which can lubricate sealing pair, reduce friction and improve lifetime. The axial pressure distribution of the V-shaped sealing are carried out by theoretical analysis and experimental testing. According to the distribution curve of axial pressure, the V-shaped sealing failure and the determination of the number of loops are discussed. <p><em> </em></p> <p><strong><em> </em></strong><em><br /></em></p

Main Pump Seal’s Characteristics Affected by Cone Angle and Clearance

Aimed at the face film characteristics of Main Pump Seal (MPS), related theoretical calculation formulas were deduced based on the Reynolds equation. A case with a certain NPPS is carried out, it is take the leakage as the basic constraint conditions, the calculation focusing on leakage, stiffness and opening force, the end cone angle and clearance change been the main changed parameters. The results show that: (1) Leakage is direct ratio with clearance of three powers;(2) Overall amount of leakage increases with the end cone angle synchronously, and in the smaller cone angle changes significantly while larger slightly; (3) film stiffness increased with clearance (cone angle) first and then decreased, and the maximum value is obtained in a certain clearance (cone angle). Finally, the preferred clearance is preferably in the range of 6~7µm, and the cone angle preferably value is 0.4~2.5'. It is provide a reliable theoretical support for MPS design and key parameter optimization, and conducive to any research related to experiment and application

Enterprise LST Algorithm Development and Its Evaluation with NOAA 20 Data

Satellite land surface temperatures (LSTs) have been routinely produced for decades from a variety of polar-orbiting and geostationary satellites, which makes it possible to generate LST climate data globally. However, consistency of the satellite LSTs from different satellite missions is a concern for such purpose; an enterprise satellite LST algorithm is desired for the LST production through different satellite missions, or at the least, through series satellites of a satellite mission. The enterprise LST algorithm employs the split window technique and uses the emissivity explicitly in its formula. This research focuses on the enterprise LST algorithm design, development and its evaluations with the National Oceanic and Atmospheric Administration&rsquo;s (NOAA) 20 (N20) Visible Infrared Imaging Radiometer Suite (VIIRS) data available since 5 January 2018. In this study, the enterprise LST algorithm was evaluated using simulation dataset consisting of over 2000 profiles from SeeBor collection and the results show a bias of 0.19 K and 0.34 K and standard deviation of 0.48 K and 0.69 K for nighttime and daytime, respectively. The in situ observations from seven NOAA Surface Radiation budget (SURFRAD) sites and two Baseline Surface Radiation Network (BSRN) sites were used for LST validation. The results indicate a bias of &minus;0.3 K and a root mean square error (RMSE) of 2.06 K for SURFRAD stations and a bias of 0.2 K and a RMSE of ~2 K for BSRN sites. Further, the cross-satellite analysis presents a bias of 0.7 K and an RMSE of 1.9 K for comparisons with AQUA MODIS LST (MYD11_L2, Collection 6). The enterprise N20 VIIRS LST product reached the provisional maturity in February 2019 and is ready for users to use in their applications

Ten Years of VIIRS Land Surface Temperature Product Validation

The Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature (LST) has been operationally produced for a decade since the Suomi National Polar-orbiting Partnership (SNPP) launched in October 2011. A comprehensive evaluation of its accuracy and precision will be helpful for product users in climate studies and atmospheric models. In this study, the VIIRS LST is validated with ground observations from multiple high-quality radiation networks, including six stations from the Surface Radiation budget (SURFRAD) network, two stations from the Baseline Surface Radiation Network (BSRN), and 13 stations from the Atmospheric Radiation Measurement (ARM) network, to evaluate its performance over various land-cover types. The VNP21A1 LST was validated against the same ground observations as a reference. The results yield a close agreement between the SNPP VIIRS LST and ground LSTs with a bias of −0.4 K and a RMSE of 1.96 K over six SURFRAD sites; a bias of −0.2 K and a RMSE of 1.93 K over two BSRN sites; and a bias of −0.1 K and a RMSE of 1.7 K over the 13 ARM sites. The time series of the LST errors over individual sites indicate seasonal cycles. The data anomaly over the BSRN site in Cabauw and the SURFRAD site in Desert Rock is revealed and discussed in this study. In addition, a method using Landsat-8 data is applied to quantify the heterogeneity level of each ground station and the results provide promising insights. The validation results demonstrate the maturity of the JPSS VIIRS LST products and their readiness for various application studies

Analysis of the Land Surface Temperature Scaling Problem: A Case Study of Airborne and Satellite Data over the Heihe Basin

This study analyzed the scaling problem of land surface temperature (LST) data retrieved with the Temperature Emissivity Separation (TES) algorithm. We compiled a remotely sensed dataset that included Thermal Airborne Hyperspectral Imager (TASI) and satellite-based Advanced Spaceborne Thermal Emission Reflection (ASTER) data, which were acquired simultaneously. This dataset provided the range of spatial heterogeneities of land surface necessary for the study, which was quantified by the dispersion variance. The LST scaling problem was studied by comparing the remotely sensed LST products in two ways. First, the LST products calculated in the distributed method and the lumped method were compared. Second, the airborne and satellite-based LST products derived from the TES algorithm were compared. Four upscaling methods of LST were used in the process. A scaling correction methodology was developed based on the comparisons. The results showed that the scaling effect could be as large as 0.8  when the spatial resolution of the TASI LST data was coarse. The scaling effect increases quickly with the spatial resolution until it reaches the characteristic scale of the landscape and is positively correlated with the spatial heterogeneity. The first two upscaling methods denoted as Methods 1–2 can upscale the LST more effectively when compared with the other two scaling methods (Methods 3–4). The scaling effect for the ASTER data is not notable. The comparison between the TASI and ASTER data showed that they were highly consistent, with a root mean square error (RMSE) of approximately 0.88 K, when the pixels were relatively homogeneous. When the spatial heterogeneity was significant, the RMSE was as large as 2.68 K  The scaling correction methodology provided resolution-invariant results with scaling effects of less than 0.5 K