Simulation of the Vibration of a Steam Generator Tube Subjected to Fluidelastic Forces Induced by Two-Phase Cross-Flow
Bibliographic record
Abstract
A computer simulation of the vibration of a tube bundle subjected to fluidelastic forces induced by two-phase cross flow is carried out. Two fluidelastic instability models are compared in the simulations: the Connors model and the quasi-steady model. In the quasi-steady model, the fluid forces are expressed in terms of the quasi-static drag and lift force coefficients and their derivatives which are determined experimentally. The consideration of the angle of incidence induced by the relative tube displacement with respect to the fluid introduces a velocity dependent term in the fluid force expression. The simulation has been done using ABAQUS. The ABAQUS user subroutine VUEL provides the required interface and information to calculate and apply the fluid forces to the structure. The fluidelastic forces applied to each element are calculated using the element displacement and velocity, the tube instantaneous frequency, a flow retardation parameter and the fluid damping and stiffness components. A typical U-tube in a steam generator subjected to a non-uniform two-phase flow was considered in the simulations. The tube support contact was modeled using the ABAQUS contact pair algorithm. The Anti-Vibration-Bars (AVB) limiting the tube vibration in the out-of-plane direction in the U-bend region were also included in this model. As the simulation was nonlinear because of the loose supports, a Fast Fourier Transform technique was used to estimate the tube instantaneous frequency. The quasi-steady fluidelastic force was compared to the fluidelastic force of the Connors model. The instability growth rate of the Connors model was found to be higher than that of the quasi-steady model. The impact forces at the supports and the AVB are also extracted. These forces can be used to calculate the work rate and estimate the tube wear.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".