Tonal Fan-Noise Radiation From Aero-Engine Bypass With Serrated End Treatments

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Hanbo Jiang ◽  
Xun Huang
Keyword(s):  
Theoretical Model ◽  
Mode Conversion ◽  
Jet Noise ◽  
Acoustic Mode ◽  
Low Noise ◽  
Fan Noise ◽  
Engine Design ◽  
Aero Engine ◽  
Parametric Studies ◽  
Hopf Method

Abstract Chevrons, which are also known as serrations, are initially developed to suppress jet noise radiating from aero-engine nozzles. The associated fluid mechanics are already well known. Compared with jet noise, turbomachinery fan noise has become relatively more important along with the ever-increasing bypass ratio. However, it is still unclear whether the trailing-edge chevrons on the bypass duct would attenuate fan noise and, if the answer is yes, what is the associated mechanism. In this work, we first use a theoretical model based on the Wiener–Hopf method to rapidly conduct parametric studies across a number of different setups. The results from such a theoretical model suggest that the chevrons are also effective in the reduction of fan noise scattering. Next, we perform high-fidelity computational fluid and acoustic simulations for a realistic aero-engine with some representative setups, and the results further confirm the effectiveness of chevrons. Both analytical and numerical results show the associated noise control mechanism, that is, chevrons would induce acoustic mode conversion (especially from low modes to high modes), which shall further result in evanescent waves in the radial direction and the final noise reduction at various radiation angles. The findings may find applications in the next-generation low-noise aero-engine design.

Theoretical model of acoustic scattering from a flat plate with serrations

2017 ◽  
Vol 819 ◽  
pp. 228-257 ◽  
Author(s):  
Xun Huang
Keyword(s):  
Theoretical Model ◽  
Practical Importance ◽  
Acoustic Scattering ◽  
Low Noise ◽  
Test Cases ◽  
Sound Waves ◽  
Rigorous Description ◽  
Parametric Studies ◽  
Closed Form Analytical Solution ◽  
Hopf Method

A theoretical model is proposed in this work to study the scattering of sound waves from a serrated flat plat in the presence of a uniform flow, which is of both scientific significance and practical importance. The key contribution is the analytic and rigorous description of the scattering from the laterally periodic serrations by incorporating Fourier series expansions and the Wiener–Hopf method, which collectively give a closed-form analytical solution. To validate and demonstrate the model, a couple of test cases with some representative sinusoidal- and sawtooth-shaped serrations are studied by comparing with a commercial finite element solver. The comparisons show quite good agreement for various set-ups. The subsequent parametric studies further demonstrate the efficiency of the model and the effect of the serrations for noise control. Overall, the proposed theoretical model should be able to assist in studies of low-noise aerofoils and the silent flying capabilities of owls.

Validating Soot Models in LES of Turbulent Flames: The Contribution of Soot Subgrid Intermittency Model to The Prediction of Soot Production in an Aero-Engine Model Combustor

2021 ◽  
Author(s):  
Lívia Pereira Tardelli ◽  
Nasser Darabiha ◽  
Denis Veynante ◽  
Benedetta Franzelli
Keyword(s):  
Gas Phase ◽  
Reference Model ◽  
Solid Phase ◽  
Phase Evolution ◽  
Turbulent Flames ◽  
Engine Model ◽  
Aero Engine ◽  
New Strategy ◽  
Parametric Studies ◽  
Soot Model

Abstract Predicting soot production in industrial systems using an LES approach represents a great challenge. Besides the complexity in modeling the multi-scale physicochemical soot processes and their interaction with turbulence, the validation of newly developed models is critical under turbulent conditions. This work illustrates the difficulties in evaluating model performances specific to soot prediction in turbulent flames by considering soot production in an aero-engine combustor. It is proven that soot production occurs only for scarce local gaseous conditions. Therefore, to obtain a statistical representation of such rare soot events, massive CPU resources would be required. For this reason, evaluating soot model performances based on parametric studies, i.e., multiple simulations, as classically done for purely gaseous flames, is CPU high-demanding for sooting flames. Then, a new strategy to investigate modeling impact on the solid phase is proposed. It is based on a unique simulation, where the set of equations describing the solid phase are duplicated. One set accounts for the reference model, while the other set is treated with the model under the scope. Assuming neglected solid phase retro-coupling on the gas phase, the soot scalars from both sets experience the same unique temporal and spatial gas phase evolution isolating the soot model effects from the uncertainties on gaseous models and numerical sensitivities. Finally, the strategy capability is proven by investigating the contribution of the soot subgrid intermittency model to the prediction of soot production in the DLR burner.

scholarly journals The Damping Capacity of a Sealed Squeeze Film Bearing

1985 ◽  
Vol 107 (3) ◽  
pp. 411-418 ◽  
Author(s):  
M. M. Dede ◽  
M. Dogan ◽  
R. Holmes
Keyword(s):  
Theoretical Model ◽  
Gas Turbine ◽  
Squeeze Film ◽  
Damping Capacity ◽  
Test Rig ◽  
Squeeze Film Damper ◽  
Aero Engine

The purpose of this paper is to establish a theoretical model to represent a sealed squeeze-film damper bearing and to assess it against results from a test rig, simulating the essential features of a medium-sized gas turbine aero engine.

Usage of Data Provenance Models in Collaborative Multi-Disciplinary Aero-Engine Design

2021 ◽  
Author(s):  
Stanislaus Reitenbach ◽  
Maximilian Vieweg ◽  
Carsten Hollmann ◽  
Richard Becker
Keyword(s):  
Data Provenance ◽  
Engine Design ◽  
Aero Engine

Systematic design and implementation of a semantic assistance system for aero-engine design and manufacturing

2021 ◽  
Vol 15 (2) ◽  
pp. 87
Author(s):  
Sonika Gogineni ◽  
Jörg Brünnhäußer ◽  
Kai Lindow ◽  
Erik Paul Konietzko ◽  
Rainer Stark ◽  
...  
Keyword(s):  
Assistance System ◽  
Systematic Design ◽  
Design And Implementation ◽  
Engine Design ◽  
Design And Manufacturing ◽  
Aero Engine

Preliminary Research on Future Smart Engine Architecture

2020 ◽  
Author(s):  
Yudong Liu ◽  
Min Chen ◽  
Hailong Tang
Keyword(s):  
Aerospace Industry ◽  
Research Projects ◽  
Engine Design ◽  
Engine Component ◽  
Aero Engine ◽  
The Future ◽  
Component Matching ◽  
Matching Mechanism ◽  
Preliminary Research ◽  
Aero Engines

Abstract Aero engines that fit the future have now increasingly attracted the attention of aerospace industry and academia. With this trend, many research projects have been carried out to explore future aero engine technologies. This paper focuses on engine design field, and aims to satisfy the future flight missions that may be unpredictably varying. However, the intrinsic strong coupling of engine component matching mechanism blocks acceleration of engine design. Under this condition, this paper comes up with the concept of smart engine architecture that via a series of engine decoupling strategies, the components can be decoupled to an extent that by properly selecting and assembling them, an engine that satisfies certain flight mission can be designed, this is named mission-oriented pluggable design mode in this paper. Following this idea, a multi-purpose engine design scheme is presented to demonstrate the potential of this engine design mode, and further value of smart engine architecture is discussed.

scholarly journals Research on the Grey Correlation Analysis of the Norm in Choosing Key Factors of Aero-engine Design Integration System

2018 ◽  
Vol 228 ◽  
pp. 03006
Author(s):  
Ying He ◽  
Rui Xiu
Keyword(s):  
Correlation Analysis ◽  
Grey Relational Analysis ◽  
Integration System ◽  
Grey Correlation ◽  
Relational Analysis ◽  
Engine Design ◽  
Aero Engine ◽  
Grey Correlation Analysis ◽  
Design Integration ◽  
Grey Relational

The key influencing factor of accurate positioning aerospace design integration system is the basis of successful construction of design architecture integration platform. Normal grey relational analysis has better approximation than general grey relational analysis. The article analyses the effects of grey correlation analysis and aero-engine design integration system, and then based on t norm grey correlation analysis, determine the key influence factors of aerospace design integration system, a more true and accurate result is obtained.

Some Novelties in Aero Engine Design

1929 ◽  
Vol 1 (8) ◽  
pp. 275-276
Author(s):  
R. Giacomelli
Keyword(s):  
Engine Design ◽  
Aero Engine
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