Effect of Rotor-Stator Spacing on Compressor Performance at Variable Operating Conditions

Self Cite

This paper investigates the clocking effect in subsonic compressor element stages and the influence of design parameters on the flow mechanism. We focus on the relationship between the wake-induced separation loss and wake mixing loss and the unsteady mechanism in the wake flow process without considering the transition through several steady and unsteady numerical simulations aimed at a series of subsonic compressor element stages. The simulation results indicate that the performance difference at various indexing positions depends on the relationship between wake mixing loss and wake-induced separation loss for different compressor designs and operating conditions. Furthermore, the pressure transport caused by the negative jet of the Stator 0 wake in Rotor 1 creates a local acceleration region called SFAF, and a decrease in its absolute flow angle reduces the Stator 1 separation. Sufficient rim work of the rotor at highly loaded operating conditions is the basis for generating an effective SFAF. Furthermore, the fore-loading blade of Rotor 1 significantly reduces suction surface pressure drop, and a small angle between the stagger angles of Stator 0 and Rotor 1 increases the unsteady rotor load caused by the upstream wake to the total rotor load, both of which enhance SFAF.

Section: Analysis Of the Baseline Stagementioning

confidence: 99%

A New Influence Mechanism of Clocking Effect in Subsonic Compressor

Niu,

Chen,

Xiang

2023

Self Cite

“…Substantial studies [5][6][7][8] have shown that such a boundary setting fosters computational stability at lower flow conditions in compressors. Furthermore, Niu et al investigated the impact of rotor-stator spacing on compressor performance across various conditions, specifying the outlet boundary as the radial profile of averaged static pressure in accordance with stable findings [9]. Moreover, Wang et al [10] examined the pipelines of two-stage centrifugal compressors, obtaining the characteristic curves by outlining the exit flow rates.…”

Section: Introductionmentioning

confidence: 98%

Development of Automated Processes for Three-Dimensional Numerical Simulation of Compressor Performance Characteristics

Liu,

Fan,

Tang

2024

Compressor characteristic evaluation is a critical step in design and optimization. Corrected characteristic curves are typically derived via experimental testing or CFD computation which is typically executed through manual manipulation. For compressors necessitating extensive characteristic computation across multiple speeds and operational conditions, the involved process is inherently complex. This paper introduces an automation approach, employing dichotomy and optimization algorithms aligned with a 3D numerical solver, to streamline the derivation of compressor characteristic curves. Initially, the paper delineated the procedural frameworks for two methodologies and validated them using a single-stage transonic compressor. Both methods achieved the automated resolution of the characteristic lines. The result indicates that the volume of the iterative computations hinges on the granularity of the space searching step and the precision in identifying the stall boundary point. Pertaining to the subject investigated herein, the dichotomy method entailed fewer iterations relative to the optimization algorithm. Subsequent adjustments to the optimization algorithmic process revealed that direct optimization mitigated computational demands substantially by reducing a cycle, thereby attesting to its superior efficacy. In summary, when simulating compressor characteristic curves, the dichotomy method proves more efficient when the interval value of the stall boundary range can be approximated. Conversely, direct optimization is preferable when the estimation of the compressor’s stall boundary is imprecise. The proposed methodologies contribute to compressor research and expedite the progression of compressor development and performance advancement.

“…Based on the acceptable boundary disturbance parameters, the influence of the total pressure and temperature on the aerodynamic response is discussed from the experimental and simulation perspectives. Niu [11] studied the influence of the operating conditions on the compressor's performance and the mechanism of dynamic and static interaction. Rzadkowski [12,13] numerically calculated the unsteady low-frequency aerodynamic forces of the blades caused by an asymmetric upstream flow.…”

Section: Introductionmentioning

confidence: 99%

Prediction Method of Unsteady Flow Load of Compressor Stator under Working Condition Disturbance

Liu

et al. 2022

Due to the complexity of the compressor operating conditions and the existence of various disturbances and unsteady effects in the flow field, the analysis of compressor stator vibration characteristics becomes particularly critical. The convolutional neural network model combined with a transient CFD method was introduced to solve the difficulty of analyzing the flow load of the compressor stator blade. This paper mainly focuses on two key points: the complex change of the aerodynamic load and the accurate prediction of the blade excitation. Considering the stator–rotor interference, the unsteady effects, and the variable working condition characteristics, the random disturbance analysis model of the flow field boundary was generated to simulate the unsteady flow excitation of the stator under complex working conditions. By establishing the neural network of boundary disturbance and flow excitation characteristics, the prediction model was trained and generated under the support of large-scale data. The most important role of the model was to establish the end-to-end data mapping between the disturbance condition and the aerodynamic load of the stator blade. The conclusions demonstrate that the introduction of an airflow disturbance is helpful to obtain the excitation characteristics of the stator under complex working conditions. The model established in this paper based on 1000 groups of disturbed working condition data can effectively predict the aerodynamic load of the blades under complex working conditions. In addition, the construction of the model is beneficial for saving a lot of computing resources, and the prediction accuracy also reaches a good level. The method presented in this paper provides a reference for the vibration analysis of the compressor stator.