The study of the annular slit flow field is important for energy consumption, transport efficiency, and the force on the capsule for hydraulic capsule transportation. A combination of physical ...experiments and theoretical analysis was used to study the annular flow field around a capsule that was set in motion at different positions of a horizontal bend pipe. We study the flow velocity distribution of the gap flow field at different bend positions of the capsule by changing the position of the capsule at the bend. We found that the distribution of the flow field remained similar for different starting positions of the capsule, but the flow velocity increased suddenly and dramatically at the inflow section of the ring gap. We recorded different velocity distributions of the annular gap on the concave and convex sides of the pipe; on the convex side, the streamline of the gap was smooth, and the change in velocity was relatively small. The flow velocity of the slit flow varied more notably on the concave side of the pipe, and there was a greater fluctuation in the flow velocity distribution. Because the effects of the capsule and the pipe on water flow were not the same, we found large fluctuations in gap flow velocity at different measuring points on the concave side. Gap flow velocity was most influenced by axial flow velocity. We found that the axial flow velocity was about one order of magnitude greater than the radial flow velocity or circumferential flow velocity. In this paper, we analyze the changes in the ring gap flow field of the capsule at different bending positions and analyze the reasons for the flow field changes and the flow velocity distribution law. This is of great significance to the study of the transport efficiency and energy consumption of the capsule. The results of this paper complement the study of capsule initiation at different positions in the bend and provide a reference point in terms of transport efficiency, energy consumption, and capsule stress. The results of this study promote the development of hydraulic capsule transportation.
Tissue repair and regenerative medicine address the important medical needs to replace damaged tissue with functional tissue. Most regenerative medicine strategies have focused on delivering ...biomaterials and cells, yet there is the untapped potential for drug-induced regeneration with good specificity and safety profiles. The Hippo pathway is a key regulator of organ size and regeneration by inhibiting cell proliferation and promoting apoptosis. Kinases MST1 and MST2 (MST1/2), the mammalian Hippo orthologs, are central components of this pathway and are, therefore, strong target candidates for pharmacologically induced tissue regeneration. We report the discovery of a reversible and selective MST1/2 inhibitor, 4-((5,10-dimethyl-6-oxo-6,10-dihydro-5H-pyrimido5,4-bthieno3,2-e1,4diazepin-2-yl)amino)benzenesulfonamide (XMU-MP-1), using an enzyme-linked immunosorbent assay-based high-throughput biochemical assay. The cocrystal structure and the structure-activity relationship confirmed that XMU-MP-1 is on-target to MST1/2. XMU-MP-1 blocked MST1/2 kinase activities, thereby activating the downstream effector Yes-associated protein and promoting cell growth. XMU-MP-1 displayed excellent in vivo pharmacokinetics and was able to augment mouse intestinal repair, as well as liver repair and regeneration, in both acute and chronic liver injury mouse models at a dose of 1 to 3 mg/kg via intraperitoneal injection. XMU-MP-1 treatment exhibited substantially greater repopulation rate of human hepatocytes in the Fah-deficient mouse model than in the vehicle-treated control, indicating that XMU-MP-1 treatment might facilitate human liver regeneration. Thus, the pharmacological modulation of MST1/2 kinase activities provides a novel approach to potentiate tissue repair and regeneration, with XMU-MP-1 as the first lead for the development of targeted regenerative therapeutics.
The piped vehicle hydraulic transportation is a new energy-saving and environmental-friendly technique for transporting materials. To optimize the technical parameters of the piped vehicle hydraulic ...transportation, the transporting energy consumption of the technique was studied by a combination of theoretical analysis and experiments. Experiments were conducted at six piped vehicles with the diameter–length ratios of 0.4, 0.6, 0.47, 0.7, 0.53, and 0.8, seven flow Reynolds numbers of 102,140, 132,413, 167,014, 200,534, 234,037, 267,556, and 299,993, two transporting loads of 1200 and 1500 g, and three pipe layout forms of straight pipe, flat bend pipe, and inclined bend pipe. The results showed that the total energy consumption of the piped vehicle hydraulic transportation increased with increasing flow Reynolds numbers and increasing mass of transporting materials. The total transporting energy consumption of a piped vehicle with the diameter–length ratio of 0.53 was the highest, and that of a piped vehicle with the diameter–length ratio of 0.47 was the lowest. The unit transporting energy consumption of a bend pipe was higher than that of a straight pipe. Meanwhile, the total energy consumption of the piped vehicle hydraulic transportation was analyzed by hydrodynamic theory. The calculation formula for the total energy consumption of the piped vehicle hydraulic transportation was obtained and validated experimentally. The maximum relative error did not exceed 8.07%, proving that the total energy consumption calculation formula of the piped vehicle hydraulic transportation was rational. By analyzing the transporting efficiency of piped vehicle hydraulic transportation under different influencing factors, the optimal transporting combination was the piped vehicle with the diameter–length ratio of z = 0.47 and the flow Reynolds number of Re = 200,534. The results of this study can provide a theoretical basis for optimizing the technical parameters of the piped vehicle hydraulic transportation.
The wheeled capsule hydraulic transportation is a new technique for transporting materials. In this technique, the wheeled capsule, which is designed to contain materials, is one of the core ...components. In this study, a new type of wheeled capsule structure was first designed, and then experiments were conducted at seven water discharges, eight wheeled capsule dimensions, and eight mass of transporting materials in the pipe with an inner diameter of 100 mm. The pipe in study was divided into nine parts, and the speed of the wheeled capsule in each pipeline section was analyzed. The results showed that the speeds of the wheeled capsules in different sections of the pipeline did not change significantly and basically fluctuate near the overall average speed and the maximum relative fluctuation value was ⩽ 8.6%. Therefore, the overall average speed of the wheeled capsule can be used to analyze the motion characteristics of the wheeled capsule. The average speed of the wheeled capsule increased with increasing water discharge, diminished with increasing mass of transporting materials, increased with increasing length of the wheeled capsule, and increased with increasing diameter of the wheeled capsule. The empirical formula of the average speed of the wheeled capsule with different water discharges, wheeled capsule dimensions and mass of transporting materials was obtained by the nonlinear regression method and can be expressed as
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. The empirical formula was experimentally validated. The maximum relative error did not exceed 7.05%, proving that the empirical formula of the average speed of the wheeled capsule was rational. The results of this study can provide a theoretical basis for designing the structure of the wheeled capsule.
The boundary layer is the main source of frictional resistance in gap flow, and the study of the flow structure characteristics of the gap flow boundary layer is of great significance for the study ...of gap flow theory. In this study, the PIV technique was utilized to experimentally investigate the gap flow boundary layers with Reynolds numbers of 16,587–56,870 and gap ratios of 0.6–0.8. The characteristics of the wall friction velocity, the boundary layer thickness, and the wall function of the gap flow boundary layer were analyzed, and the influences of the mean velocity of the gap flow and the gap ratio on the flow structure characteristics of the boundary layer were explored. The results show that using PIV to measure the velocity profile in the viscous sub-layer to solve for the wall friction velocity had good precision. The boundary layer thickness was inversely proportional to the mean velocity of the gap flow and the gap ratio. The wall functions of the boundary layer were as follows: in the viscous sub-layer (y+< 5.5), u+=y+; in the transition layer (5.5 <y+< 26), u+=10.071tanh0.071y+; and in the logarithmic layer (y+> 26), u+=2.78lny++3.8. The thickness of the logarithmic layer was proportional to the mean velocity of the gap flow and inversely proportional to the gap ratio. The inner region of the boundary layer extended to y< 0.18δ or y< 0.13(h/2).
Hydraulic pipeline transportation of a piped vehicle is a new mode of transportation with energy-saving potential and environmental protection. In order to analyze the turbulent characteristics of ...the flow around the piped vehicle, a large eddy simulation (LES) method was adopted to simulate the hydraulic characteristics and vortex characteristics of the flow at a Reynolds number of Re = 140,467 with diameter-to-length ratios of 0.4, 0.5, 0.6, and 0.7. The results showed that the main factor that affected the gap flow velocity, the backflow area length, and the turbulence intensity was the cylinder diameter in the diameter-to-length ratio of the piped vehicle. The backflow area lengths for piped vehicles with different diameter-to-length ratios were all less than 1 D, and the axial disturbance distances were about 7.5 D. In addition, a variety of vortex structures existed in the gap flow and the rear flow areas. At the beginning of vortex development, ring vortices were generated at the front and rear ends of the cylinder body. Subsequently, the front ring vortex fell off along the cylinder body and evolved into hairpin vortices. At the same time, a reflux vortex was formed after the rear ring vortex broke away from the cylinder body, and wake vortices were generated behind the rear supports. Finally, some worm vortices were dispersed from the wake vortices. These results can further improve the theoretical system for the hydraulic pipeline transportation of piped vehicles and can provide a theoretical basis for industrial application.
It is of great significance to explore the flow velocity characteristics of piped cars when they are started under different loads. In this paper, the flow velocity characteristics of the water flow ...around a piped car when it is started in the straight pipe section are studied through physical experiments. The masses of the piped cars are 1.5 kg, 1.9 kg, and 2.3 kg, respectively. The results show that, with the increase in the load of the pipeline car, the axial flow velocity in the front section increases, the absolute values of radial flow velocity and circumferential flow velocity increase, and the gradient of flow velocity increases. The positive radial flow velocity and negative circumferential flow velocity regions increase, and the distribution of positive and negative radial flow velocities and circumferential flow velocities is obvious. The gradients of axial, radial, and circumferential flow velocities in the annular section all increase, and the contour spacing becomes smaller and more densely distributed. The absolute values of the radial and circumferential flow velocities increase. The regional demarcation of axial flow velocity in the rear section is more obvious, and the average value of axial flow velocity in the high-flow-velocity area behind the vehicle increases. Additionally, the gradient of flow velocity increases. The absolute values of radial velocity and circumferential velocity increase, the gradient of velocity increases, and the velocity distribution is obviously regional. This study supplements and improves the theoretical study of a piped car when it is started and has certain reference value for the research and application of the hydraulic transport technology of the barrel-loading pipeline.
The step-type energy dissipator is widely used to construct small- and medium-sized reservoirs with its high energy dissipation rate. In order to further improve its air entrainment characteristics ...and energy dissipation, and reduce the influence of cavitation, in this paper, we added a trapezoidal energy dissipation baffle block at the convex corner of the traditional step to form a trapezoidal energy dissipation baffle block-step combination energy dissipator. We used a combination of hydraulic model experiments and numerical simulation to study the hydraulic characteristics. The results showed that the trapezoidal energy dissipation baffle block-step combination energy dissipator initial entrainment point, with the increase in flow rate, gradually moved backward. A step horizontal surface pressure change in the cavity recirculation area showed a prominent “V” shape; in front of the trapezoidal energy dissipation baffle block, there was a rising trend, and in the energy dissipation baffle block gap, there was a declining trend. The step vertical surface pressure showed a decreasing trend, and negative pressure appeared near the convex angle. The cross-section velocity distribution presented a trend of being small at the bottom and large at the surface, with a large velocity gradient in the longitudinal section of the energy dissipation baffle block and a small velocity gradient in the longitudinal section of the nonenergy dissipation baffle block. The energy dissipation rate reached more than 70% within the test range, and the energy dissipation rate gradually decreased with the increase in the flow rate. The combined energy dissipator is conducive to reducing the cavitation hazard and improving the energy dissipation effect, providing a reference for engineering design and existing step energy dissipators to remove risks and reinforcement.
Hydrodynamic forces influence the efficiency and safety of pipeline transport in ocean engineering. A capsule pipeline is an example of pipeline transportation. In this work, a dynamic model is ...proposed to explain the oscillating motion of a capsule in a hydraulic capsule pipeline (HCP). The main study was conducted using a modal analysis of hydrodynamic forces acting on a capsule, which could be divided into frictional drag and pressure drag forces. The results indicated the presence of independent modes with different contributions to the hydrodynamic forces. Ultimately, the first to fiftieth modes represented 94~97.3% of the hydrodynamic force contributions. These modes had their own frequency ranges and power spectrum density (PSD) functions, and the frictional drag and pressure drag were both found to coincide with the narrow-band characteristics of the lower-order modes. However, the PSD functions of the frictional drag were found to fulfill the wide-band characteristics corresponding to the higher-order modes. Then, coherent structures were extracted. As the mode order increased, the vortices became more fragile and the frequency became higher. This phenomenon coincided with an increase in the frequency of the time coefficient peak, which became larger. This work could provide new perspectives on the hydrodynamic forces of pipeline transport, especially its dynamic analysis of the interaction between a rigid capsule and fluid flow.
In the design process for a two-pipe vehicles transportation system, some simple mathematical models are required to quickly calculate the main characteristics of the system. For this purpose, an ...easy-to-handle mathematical model for the concentric annular gap flow is proposed, and the velocity expression for the concentric annular gap flow is solved using cylindrical coordinates. According to the force characteristics of the two-pipe vehicles, a mathematical model of the two-pipe vehicle motion is established, and the motion and force balance equations of the two-pipe vehicles are deduced. The experimental results are in good agreement with the model results. The factors affecting the two-pipe vehicles movement speed are analyzed, and the standard regression coefficient method in multiple regression analysis is used to determine the influence degree of each factor on the movement speed of the two-pipe vehicles. The research presented in this paper not only enriches the annular gap flow theory, but also provides a theoretical reference for the development of the two-pipe vehicles transportation technology and provides technical support for the realization of relevant industrial applications.
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