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With the rapid growth of agricultural trade volumes, the transportation of agricultural products has received widespread attention from society. Aiming at these problems of low transport efficiency and high transport cost in long-distance transport of agricultural products, an energy-saving and environmental-friendly transport mode of agricultural machinery-hydraulic capsule pipelines (HCPs)-was proposed. HCPs effectively solve issues like traffic congestion, energy crises, and atmospheric pollution. Published literature is mainly limited to the capsule speed and the pressure drop characteristics of the fluid within the pipelines. This research was conducted on the following four aspects of HCPs. Firstly, the structure of the carrier was improved and called a 'piped carriage'. Secondly, a coupled solution between the structural domain of the piped carriage and the fluid domain within the pipelines was numerically investigated by using the commercial CFD software ANSYS Fluent 12.0 based on the bidirectional fluid-structure interaction methods. Thirdly, the effects of guide vane placement angle on hydraulic characteristics of the internal flow field within the horizontal pipelines transporting the piped carriage were extensively evaluated. Finally, based on least-cost principle, an optimization model of HCPs was established. The results indicated that the simulated results were in good agreement with the experimental results, which further demonstrated that it was feasible to adopt the bidirectional fluid-structure interaction methods for solving the hydraulic characteristics of the internal flow field when the piped carriage was moving along the pipelines. This article will provide an abundant theoretical foundation for the rational design of HCPs and its popularization and application.

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Energy shortage restricts the rapid development of the global transport industry. Trying to develop innovative modes of transport becomes an inevitable trend. Hydraulic Capsule Pipelines (HCPs) are the freight transportation modes that use a kind of fluid to push capsules filled with bulk solids materials through water-filled pipelines. HCPs not only alleviate everincreasing costs caused by energy scarcities and oil price up, but also solve issues like traffic congestion and environmental pollution. Published literature is mainly limited to numerical simulation of the unidirectional fluid-structure interaction between the capsules and the fluid inside the pipelines; furthermore, the hydraulic characteristics only involve the speed of the capsules and the pressure drop characteristics of the fluid within the pipe. This research was conducted on the following four aspects of HCPs. First, an improved cylindrical capsule called a “piped carriage” was evaluated. Second, an associated solution between the fluid domain within the pipe and the solid domain of the piped carriage was investigated numerically on the basis of the bidirectional fluid-structure interaction methods. Third, the effects of diameter ratio b (ratio of a diameter of the piped carriage De to a pipe diameter Dp, widely ranging in b=0.4~0.95) on hydraulic characteristics of transporting the piped carriage within the pipeline were extensively discussed. Finally, based on Least-Cost Principle, an optimization model of HCPs was effectively built. The results showed that the simulated results were in good agreement with the experimental results, which further indicated that it was feasible for solving the hydraulic characteristics of transporting the piped carriage by using the bidirectional fluid-structure interaction methods. The results will be of great reference value for further research on HCPs and also provide a theoretical foundation for the optimal design of HCPs.

A boring bar is a tool used to install cutters and transfer power during boring. Because the boring bar in a narrow workspace is usually slender, chatter often occurs in the boring process. To improve the chatter stability of the boring bar, researchers have designed composite material boring bars with high dynamic stiffness to meet the requirements of high-speed boring. However, the effect of the shear deformation and rotational inertia were ignored. In this paper, a model of a composite boring bar considering shear deformation and rotational inertia is established based on the Adomian Modified Decomposition Method (AMDM). The dynamic characteristics, such as the vibration mode shapes, natural frequency, and chatter stability of the composite boring bar considering the shear deformation and rotational inertia, are analyzed comprehensively. The analysis results show that, when the shear deformation and rotational inertia are considered, the composite boring bar can exhibit different vibration mode shapes. Moreover, the natural frequencies and the cutting depth will be reduced. The results are helpful to improve the understanding about dynamic characteristics of the composite boring bar, and to provide guidance for designing of boring bars. Moreover, accurate adjustment of the cutting speed and depth in CNC boring can be based on the analysis results.