A Summary of High-Fidelity Numerical Studies of Flow Acoustic Resonant Interactions in Transitional Airfoils

ABSTRACTThis paper presents a survey of published works on ducted fans for aeronautical applications. Early and recent experiments on full- or model-scale ducted fans are reviewed. Theoretical studies, lower-order simulations and high-fidelity CFD simulations are also summarised. Test matrices of several experimental and numerical studies are compiled and discussed. The paper closes with a summary of challenges for future ducted fan research.

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Investigation of the ship–seabed interaction with a high-fidelity CFD approach

Journal of Marine Science and Technology ◽

10.1007/s00773-020-00786-7 ◽

2020 ◽

Author(s):

Weichao Shi ◽

Mingxin Li ◽

Zhiming Yuan

Keyword(s):

Computational Cost ◽

Prediction Method ◽

Simulation Method ◽

High Fidelity ◽

Long Distance ◽

Sliding Mesh ◽

Numerical Studies ◽

Wave Development ◽

Seabed Interaction ◽

Ship Performance

AbstractShip–seabed interaction is highly critical to ship safety and ship performance when ship operates over shallow water with uneven seabed. However, the prediction method for ship reaction is still yet to be fully developed. In this paper, a high-fidelity transient numerical simulation method with sliding mesh is developed based on computational fluid dynamics to model a vessel passing a step bank, demonstrating to be a computational cost economical solution. The comprehensive numerical model is validated and verified against benchmarked experimental and numerical studies, which is proved to be highly accurate in predicting force characteristics and wave development. Meanwhile, during the research the impulse effect generated by the step bank was found to have striking effects on the wave elevation, wake development and vessel sinkage. Five regions on the behaviour of vessel sinkage are defined in the present work. According to the result, the vessel will encounter the extreme sinkage after a relatively long distance (12 $${L}_{\mathrm{pp}}$$ L pp at $${F}_{h2}=0.519$$ F h 2 = 0.519 ) passing the step bank instead of immediately.

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Sensitivity Analysis of High-Frequency Forced Response for Mistuned Bladed Discs Based on High-Fidelity Models

Volume 7A: Structures and Dynamics ◽

10.1115/gt2016-57690 ◽

2016 ◽

Author(s):

Yuanqiu Tan ◽

Chaoping Zang ◽

Biao Zhou ◽

Yongliang Duan ◽

E. P. Petrov

Keyword(s):

Sensitivity Analysis ◽

Response Surface ◽

High Frequency ◽

Natural Frequencies ◽

Realistic Model ◽

Forced Response ◽

Explicit Representation ◽

High Fidelity ◽

Effective Response ◽

Numerical Studies

This paper proposes an effective method for sensitivity analysis of forced response of bladed discs to blade mistuning. The numerical studies of forced response of a turbine bladed disc vibrating in the frequency ranges corresponding to resonances with higher modes are also presented. The blade mistuning is modelled by specially defined mistuning matrices used for simulating experimentally measured scatter of blade natural frequencies. Based on this method, the sensitivity of forced response amplitude levels are studied for displacements and stress levels for a realistic model of a bladed disc. The effective response surface techniques are developed for explicit representation of the mistuned forced response as a function of blade mistuning elements.

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Chaotic Dynamics in a Quantum Fermi–Pasta–Ulam Problem

Entropy ◽

10.3390/e21010051 ◽

2019 ◽

Vol 21 (1) ◽

pp. 51 ◽

Cited By ~ 2

Author(s):

Alexander Burin ◽

Andrii Maksymov ◽

Ma’ayan Schmidt ◽

Il’ya Polishchuk

Keyword(s):

Chaotic Dynamics ◽

Chaotic Behavior ◽

High Energy ◽

Exact Diagonalization ◽

Low Energy ◽

Periodic Systems ◽

Resonant Interactions ◽

Numerical Studies ◽

Anharmonic Vibrations ◽

Atomic Chains

We investigate the emergence of chaotic dynamics in a quantum Fermi—Pasta—Ulam problem for anharmonic vibrations in atomic chains applying semi-quantitative analysis of resonant interactions complemented by exact diagonalization numerical studies. The crossover energy separating chaotic high energy phase and localized (integrable) low energy phase is estimated. It decreases inversely proportionally to the number of atoms until approaching the quantum regime where this dependence saturates. The chaotic behavior appears at lower energies in systems with free or fixed ends boundary conditions compared to periodic systems. The applications of the theory to realistic molecules are discussed.

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Using the Theory of Planned Behavior to Predict Faking in Selection Exercises Varying in Fidelity

Journal of Personnel Psychology ◽

10.1027/1866-5888/a000211 ◽

2018 ◽

Vol 17 (3) ◽

pp. 155-160 ◽

Cited By ~ 3

Author(s):

Daniel Dürr ◽

Ute-Christine Klehe

Keyword(s):

Theory Of Planned Behavior ◽

Planned Behavior ◽

Predictive Validity ◽

Group Discussion ◽

Role Play ◽

Selection Procedure ◽

High Fidelity ◽

Selection Research ◽

Play Group

Abstract. Faking has been a concern in selection research for many years. Many studies have examined faking in questionnaires while far less is known about faking in selection exercises with higher fidelity. This study applies the theory of planned behavior (TPB; Ajzen, 1991 ) to low- (interviews) and high-fidelity (role play, group discussion) exercises, testing whether the TPB predicts reported faking behavior. Data from a mock selection procedure suggests that candidates do report to fake in low- and high-fidelity exercises. Additionally, the TPB showed good predictive validity for faking in a low-fidelity exercise, yet not for faking in high-fidelity exercises.

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