| LDV is used to test hydraulic pipeline capsule under different load conditions,turbulent characteristics of the flow field behind the moving capsule is studiedthrough theoretical analysis and experimental study. Truth obtained by theanalysis answers can provide a theoretical basis for the further hydraulictransportation of material and production design. This paper is based on theNational Natural Science Foundation of China,“Pipeline HydraulicTransportation Energy Consumption of Train”（51179116）. Main results showedas follows:1. While a capsule filled in different loads operating in the straight andhorizontal pipeline，the contour of the axial velocity distribution was kind ofconcentric ring structure; values of axial velocity values reduces from the centerarea to the outer ring, the position of center ring moves slightly; the overalldirection of the radial velocity pointed to the center point of the test section,radial velocity distribution showed irregular sample strips and distributeddisorderly；with the increase of load the radial velocity distribution showed nosignificant phenomenon; overall circumferential direction of pipe-flow isclockwise，the speed value of the central area is larger than the outer ring’svelocity value;2. Measuring points located close to the side walls of the test section(45,120°)，its axial velocity is significantly smaller than the axial velocity ofthe other three measuring points; as the transport load increases, the axial velocity appears no significant fluctuations, special measuring point fluctuationsshowed the same trend; with the transport load increases, the radial velocity ofthe capsule was affected significantly; but there is no qualitative law; radialvelocity of the center measuring point (0,0°) showed a steady trend;3. In the overall trend, axial velocity of the measuring points on the the polaraxis is greater than the peripheral velocity, the peripheral speed is greater thanthe radial velocity; with the change of polar radius, the values of radial velocityand circumferential velocity value showed no significant change; with transportload increases, the axial speed of side wall measuring point is less than the axialvelocity of the center region; this phenomenon is consistent with condition whilethere is no capsule in the pipeline; with the increased delivery load, axialvelocity of the center measuring point (0,0°) and measuring point near thecenter region reduces slightly;4. Because of the intervention of the moving capsule, pipeline flow promotesits cross-section so that it can keep the operating situation, and this processgenerates complex energy exchange. Variation of the fluctuating velocity afterthe moving capsule has changed, where the greatest impact is the test section ofthe central region; two capsule models in the same transport loads and Reynoldsconditions showed different axial fluctuation intensity;5. With increasing transport load, axial fluctuating velocity of the centermeasuring point (0,0°) significantly increased; radial and circumferentialfluctuating velocity intensity showed no obvious change with the increasing load;radial and circumferential velocity intensity kept a stable situation along withchanges in the position on the testing section, but intensity of the axialfluctuating velocity showed a totally different phenomenon;6. The moving capsule changes flow fluctuation intensity of pipeline flow, butonly axial fluctuating velocity intensity changes with the increasing loadobviously. Therefore, the energy consumption and loss may largely caused bythe axial flow turbulence; 7. There is a significant slow axial velocity region in the central region, andthe average slow axial velocity decreases with the increasing load;Result of this paper may provide some object basis for further study of thecapsule pipeline transportation operating in the straight and horizontal pipeline. |
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