# Analysis of Cyclone Spinning Effect with Different Guide Vane Heights
## 1 Introduction  
Many rivers in China have a large capacity for sediment transport, and the sediment deposition situation is severe [1]. Constructing hydraulic structures on these sandy rivers can weaken the river's ability to automatically regulate the balance of water and sediment, leading to a large amount of sediment deposition on the riverbed. This can severely affect the storage capacity, safe operation, and service life of reservoirs. To enhance the sand-carrying capacity of pipelines, a method of transporting sediment with spiral flow in circular pipes has been proposed. In order to further explore the mechanism of solid transport by spiral flow, extensive research has been conducted on the generation and development of spiral flow. As early as the 1950s, [PERSON] [2] demonstrated the feasibility of vortex tube sediment removal measures. [PERSON] [3], [PERSON] [4], and others studied the decay of spiral flow intensity, and the results showed that the decay of spiral flow intensity can be approximated by an exponential function. [PERSON] [5] and others studied the impact of Reynolds number, spiral flow generator length, and the pipe length-to-diameter ratio on heat transfer enhancement and pressure drop for decaying swirls in circular pipes, and the results showed that the introduction of swirling led to a significant enhancement of air flow in heat transfer. China began to pay attention to vortex tube sediment removal measures in the 1970s. [PERSON] [6; 7] and others started researching spiral flow sediment removal technology early on, analyzing the impact of channel slope, average flow velocity, flow rate, and other factors on swirl intensity and sediment removal effects. [PERSON] [8] summarized and generalized the progress of vortex tube sediment removal research, introducing progress in analyzing the mechanism of vortex tube sediment removal, sediment removal efficiency calculation, the design principles and processes of vortex tubes, and important parameters affecting the sediment removal capacity of vortex tubes. The guide vane swirler is a commonly used device for generating spiral flow. [PERSON] [9; 10] and others found that when studying velocity distribution at the outlet section of the swirler, the axial velocity presents a logarithmic-type distribution, while the circumferential velocity in the main flow area is approximately linearly distributed, and the outlet section pressure is approximately distributed as a rotating paraboloid. [PERSON] [11] studied the follow-up swirler in circular pipe spiral flow, set the structural parameters of the follow-up swirler, and studied the impact of the follow-up swirler on the rotating flow field, verifying that the follow-up swirler had a continued swirling effect on the already decayed circular pipe spiral flow. [PERSON] [12; 13] and others introduced the structural forms and performance characteristics of different forms of spiral flow generation devices and studied the velocity characteristics and pressure change rules of pipe swirls. [PERSON] [14; 15] and others conducted a large number of experiments on horizontal pipe spiral flow, confirming the theoretical derivation of the linear distribution of tangential velocity at the cross-section and revealing the law of axial velocity distribution. [PERSON] [16] and others used Fluent and other software for motion simulation of pipeline slurry spiral flow, and the results showed that the simulation values basically conformed to the motion law of pipeline slurry. [PERSON] [17] and others used the Aerospace Computational Simulation Unified Platform (UPACS) to study the velocity components at the pressurized air inlet of the annular slit upstream reservoir, clarifying the mechanism of spiral nozzle flow.