Tension leg vortex induced vibration test device under bidirectional shear flow and bidirectional step shear flow

Abstract

The invention provides a tension leg vortex-induced vibration test device under bidirectional shear flow and bidirectional stepped shear flow in the technical field of ocean engineering. The device of the invention comprises a tension leg model mechanism, a measurement and analysis module, a driving module, a cantilever module, a bottom supporting module, a flow baffle module and a sliding groove module, wherein the tension leg model mechanism is fixed on the cantilever module via a specially-designed fixing end; each two of the bottom supporting module, the driving module and the cantilever module are vertically connected; the flow baffle module is fixed on the cantilever module via a support; the bottom supporting module is fixed on a water tank steel lifting bottom via a high-strength bolt; the sliding groove module is fixed on the bottom supporting module via a bolt; the cantilever is driven by the driving module to rotate; and each measurement instrument of the measurement and analysis module is arranged in the tension leg model mechanism and the cantilever module in a disperse mode. The device of the invention is convenient to assemble and disassemble, low in the complexity degree, and high in flexibility, and can simulate an actual-scale tension leg and a shear flow field.

Description

technical field [0001] The invention relates to a device in the technical field of marine engineering, in particular to a vortex-induced vibration testing device for a tension leg of a flexible pipe model in a deep pool of marine engineering under bidirectional shear flow and bidirectional stepped shear flow. Background technique [0002] The solitary wave in the ocean is a typical severe sea state that commonly exists in density-stratified oceans. It has the characteristics of large amplitude, long duration, and nonlinearity. For the tension leg platform, the frequently active internal waves will not only produce a huge impact load on the tension leg, but also make it bear the action of bidirectional shear flow or bidirectional step shear flow, resulting in vortex induced vibration. The so-called vortex-induced vibration refers to a columnar structure in a certain velocity incoming flow, and alternate vortex shedding will occur on both sides of it. The columns are subject ...

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Problems solved by technology

[0003] At present, domestic and foreign academic circles and engineering circles have little research on the phenomenon of tension leg vortex induced vibration in the internal wave flow field. They are generally divided into two methods: model test and numerical simulation. There are many problems in the direct numerical simulation of vortex induced vibration. Empirical model forecasting software such as SHEAR7 has defects such as low efficiency and poor accuracy, and the results obtained by the forecast are often far from the test results, which need to be evaluated and corrected

The vortex-induced vibration phenomenon of the tension leg can be better studied by the experimental method, and some progress has been made in the past period of time, but in general there are still the following deficiencies: 1. Generally, only small-scale pipe fittings can be simulated. Vibration, it is difficult to effectively conduct vortex-induced vibration tests at real Reynolds numbers

2. Generally, only the vortex-induced vibration of the tension leg in the uniform flow field can be simulated, but the vortex-induced vibration of the tension leg in the shear flow field cannot be simulated

3. The device is relatively complicated and bulky, inconvenient to install, and requires a large motor power

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