Prediction of the Acoustic Reflection in a Realistic Aeroengine Intake With Three Numerical Methods to Analyze Fan Flutter

2021 ◽  
pp. 1-20
Author(s):  
Thomas Bontemps ◽  
Stephane Aubert ◽  
Maxime de Pret
Keyword(s):  
Analytical Model ◽  
Design Process ◽  
Cfd Simulation ◽  
Computational Cost ◽  
Fidelity Level ◽  
Acoustic Reflection ◽  
Acoustic Coupling ◽  
Air Intake ◽  
Operating Points ◽  
Do So

Abstract For a particular range of frequencies, an acoustic coupling between the fan and the air intake can modify fan stability regarding flutter. Previous works have shown that characterizing the reflection on the intake opening might be a cru- cial element to target operating points for which the risk of acoustic driven flutter is high. To do so, three methodologies are compared in this paper: an aeroelastic CFD simulation, an acoustic potential simulation and an analytical model. Each of them has a different fidelity level and computational cost, what makes their usage more beneficial at some step in the design process. It is shown that results of aeroelastic CFD and acoustic potential simulations are in excellent agreement. Fast acoustic simulations are then a good option in the early design process. The analytical model presents an important error mainly on the phase, and should be adapted before usage.

Prediction of the Acoustic Reflection in a Realistic Aeroengine Intake With Three Numerical Methods to Analyze Fan Flutter

2020 ◽  
Author(s):  
Thomas Bontemps ◽  
Stéphane Aubert ◽  
Maxime de Pret
Keyword(s):  
Analytical Model ◽  
Design Process ◽  
Cfd Simulation ◽  
Computational Cost ◽  
Fidelity Level ◽  
Acoustic Reflection ◽  
Acoustic Coupling ◽  
Air Intake ◽  
Operating Points ◽  
Do So

Abstract For a particular range of frequencies, an acoustic coupling between the fan and the air intake can modify fan stability regarding flutter. Previous works have shown that characterizing the reflection on the intake opening might be a crucial element to target operating points for which the risk of acoustic driven flutter is high. To do so, three methodologies are compared in this paper: an aeroelastic CFD simulation, an acoustic potential simulation and an analytical model. Each of them has a different fidelity level and computational cost, what makes their usage more beneficial at some step in the design process. It is shown that results of aeroelastic CFD and acoustic potential simulations are in excellent agreement. Fast acoustic simulations are then a good option in the early design process. The analytical model presents an important error mainly on the phase, and should be adapted before usage.

Investigation of Turbulence Modeling and Harmonic Balance Methods Towards Accurately Predicting Compressor Flow Fields

2020 ◽  
Author(s):  
Liam McManus ◽  
Justin Hodges ◽  
Ilyas Beary
Keyword(s):  
Harmonic Balance ◽  
Cfd Simulation ◽  
Turbulence Modeling ◽  
Fluid Dynamic ◽  
Computational Cost ◽  
Sensitivity Study ◽  
Peak Efficiency ◽  
Transonic Compressor ◽  
Unsteady Effects ◽  
Operating Points

Abstract Numerical investigations of the NASA stage 37 compressor case are presented. Simcenter STAR-CCM+ is used for RANS based aerodynamic quantifications of the transonic compressor, with specific attention to the near stall and the peak efficiency operating points. In these axial turbomachines, the unsteady effects are non-trivial, and need to be accounted for in the design methods. Typically, transient simulation of fully realistic engine hardware is unrealistic in terms of the computational expense. However, using a harmonic balance approach in computational fluid dynamic (CFD) simulation has been shown to have a proficiency in capturing the dominant unsteady behaviors at a relatively lower computational cost. As such, the performance of the NASA stage 37 compressor is characterized with both steady and harmonic balance approaches. Furthermore, a thorough exploration and sensitivity study on the turbulence modeling is conducted. The lag elliptic blending k-ε turbulence model is considered, due to its capability for improved predictions in highly separated turbomachinery flows, as compared to the k-O SST and k-O BSL model results.

scholarly journals A MODEL OF CREATIVE HERITAGE FOR INDUSTRY: DESIGNING NEW RULES WHILE PRESERVING THE PRESENT SYSTEM OF RULES

2021 ◽  
Vol 1 ◽  
pp. 141-150
Author(s):  
Honorine Harlé ◽  
Pascal Le Masson ◽  
Benoit Weil
Keyword(s):  
Case Studies ◽  
Design Process ◽  
Industry 4.0 ◽  
Innovation Management ◽  
Present System ◽  
Innovative Capability ◽  
Current Change ◽  
A Site ◽  
Do So

AbstractIn industry, there is at once a strong need for innovation and a need to preserve the existing system of production. Thus, although the literature insists on the necessity of the current change toward Industry 4.0, how to implement it remains problematic because the preservation of the factory is at stake. Moreover, the question of the evolution of the system depends on its innovative capability, but it is difficult to understand how a new rule can be designed and implemented in a factory. This tension between preservation and innovation is often explained in the literature as a process of creative destruction. Looking at the problem from another perspective, this article models the factory as a site of creative heritage, enabling creation within tradition, i.e., creating new rules while preserving the system of rules. Two case studies are presented to illustrate the model. The paper shows that design in the factory relies on the ability to validate solutions. To do so, the design process can explore and give new meaning to the existing rules. The role of innovation management is to choose the degree of revision of the rules and to make it possible.

CFD Simulation of a Supercritical Carbon Dioxide Radial-Inflow Turbine, Comparing the Results of Using Real Gas Equation of Estate and Real Gas Property File

2016 ◽  
Vol 846 ◽  
pp. 85-90 ◽  
Author(s):  
Mostafa Odabaee ◽  
Emilie Sauret ◽  
Kamel Hooman
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Cfd Simulation ◽  
Pressure Ratio ◽  
Computational Cost ◽  
Real Gas ◽  
Table Method ◽  
Radial Inflow Turbine ◽  
Solar Resource ◽  
Supercritical Carbon

The present study explores CFD analysis of a supercritical carbon dioxide (SCO2) radial-inflow turbine generating 100kW from a concentrated solar resource of 560oC with a pressure ratio of 2.2. Two methods of real gas property estimations including real gas equation of estate and real gas property (RGP) file - generating a required table from NIST REFPROP - were used. Comparing the numerical results and time consumption of both methods, it was shown that equation of states could insert a significant error in thermodynamic property prediction. Implementing the RGP table method indicated a very good agreement with NIST REFPROP while it had slightly more computational cost compared to the RGP table method.

Toward a Reasoning Framework of Design As Synthesis

1999 ◽  
Author(s):  
Masaharu Yoshioka ◽  
Tetsuo Tomiyama
Keyword(s):  
Decision Making ◽  
Problem Solving ◽  
Design Process ◽  
Process Modeling ◽  
Implementation Strategy ◽  
Multiple Model ◽  
Hypothetical Reasoning ◽  
Design Processes ◽  
Design Process Modeling ◽  
Do So

Abstract Most of the previous research efforts for design process modeling had such assumptions as “design as problem solving,” “design as decision making,” and “design by analysis,” and did not explicitly address “design as synthesis.” These views lack notion and understanding about synthesis. Compared with analysis, synthesis is less understood and clarified. This paper discusses our fundamental view on synthesis and approach toward a reasoning framework of design as synthesis. To do so, we observe the designer’s activity and formalize knowledge operations in design processes. From the observation, we propose a hypothetical reasoning framework of design based on multiple model-based reasoning. We discuss the implementation strategy for the framework.

scholarly journals Estimation and Mitigation of Unknown Airplane Installation Effects on GPA Diagnostics

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 36
Author(s):  
Mikael Stenfelt ◽  
Konstantinos Kyprianidis
Keyword(s):  
Design Process ◽  
Gas Turbines ◽  
Diagnostic System ◽  
Power Extraction ◽  
Installation Effects ◽  
Degradation Pattern ◽  
Shaft Power ◽  
Air Intake ◽  
Intake Pressure ◽  
Diagnostic Framework

In gas turbines used for airplane propulsion, the number of sensors are kept at a minimum for accurate control and safe operation. Additionally, when data are communicated between the airplane main computer and the various subsystems, different systems may have different constraints and requirements regarding what data transmit. Early in the design process, these parameters are relatively easy to change, compared to a mature product. If the gas turbine diagnostic system is not considered early in the design process, it may lead to diagnostic functions having to operate with reduced amount of data. In this paper, a scenario where the diagnostic function cannot obtain airplane installation effects is considered. The installation effects in question is air intake pressure loss (pressure recovery), bleed flow and shaft power extraction. A framework is presented where the unknown installation effects are estimated based on available data through surrogate models, which is incorporated into the diagnostic framework. The method has been evaluated for a low-bypass turbofan with two different sensor suites. It has also been evaluated for two different diagnostic schemes, both determined and underdetermined. Results show that, compared to assuming a best-guess constant-bleed and shaft power, the proposed method reduce the RMS in health parameter estimation from 26% up to 80% for the selected health parameters. At the same time, the proposed method show the same degradation pattern as if the installation effects were known.

scholarly journals Wave Propagation in Thin-Walled Aortic Analogues

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
C. G. Giannopapa ◽  
J. M. B. Kroot ◽  
A. S. Tijsseling ◽  
M. C. M. Rutten ◽  
F. N. van de Vosse
Keyword(s):  
Experimental Data ◽  
Wave Propagation ◽  
Frequency Domain ◽  
Analytical Model ◽  
Viscoelastic Properties ◽  
Numerical Models ◽  
Computational Cost ◽  
One Dimensional ◽  
Arterial Blood

Research on wave propagation in liquid filled vessels is often motivated by the need to understand arterial blood flows. Theoretical and experimental investigation of the propagation of waves in flexible tubes has been studied by many researchers. The analytical one-dimensional frequency domain wave theory has a great advantage of providing accurate results without the additional computational cost related to the modern time domain simulation models. For assessing the validity of analytical and numerical models, well defined in vitro experiments are of great importance. The objective of this paper is to present a frequency domain analytical model based on the one-dimensional wave propagation theory and validate it against experimental data obtained for aortic analogs. The elastic and viscoelastic properties of the wall are included in the analytical model. The pressure, volumetric flow rate, and wall distention obtained from the analytical model are compared with experimental data in two straight tubes with aortic relevance. The analytical results and the experimental measurements were found to be in good agreement when the viscoelastic properties of the wall are taken into account.

A Heritage Approach to Risk Based Design

2000 ◽  
Author(s):  
Joseph R. Fragola
Keyword(s):  
Design Process ◽  
Great Difficulty ◽  
Aerospace Systems ◽  
The Individual ◽  
Mind's Eye ◽  
Further Development ◽  
Do So

Abstract Designers seldom, if ever, create designs “out of whole cloth”. They might begin with a clean piece of paper but their designs, no matter how creative or pioneering, must always embrace the technological heritage within which they are imbedded, at least to a degree. If they fail to do so they will almost certainly have great difficulty in being implemented, and even greater difficulty being successful. In this way the words “heritage” and “risk” have been linked, since time immemorial, in the design process and therefore in the designer’s mind’s eye. While this linkage is, in this sense, nothing new, the linkage has until recently been done heuristically and informally based upon the judgment and expertise of the individual designer, perhaps supplemented by the judgment and expertise of those peers of personal acquaintance. Recently, as an outgrowth of the broader application of probabilistic technology, a more formal and systematic link between design heritage and design risk has been attempted. While the number of actual applications are few, those that have been attempted seem to forecast that significant benefits might accrue from further development of the concept and its wider application especially in the case of the advanced technical designs so characteristic of aerospace systems. While the process of risk-based design is still in development, the individual steps in the process are beginning to evolve. These steps, which are listed in summary form in Figure 1 below, will be discussed in the presented paper as they apply to the design of a container to return samples from Mars.

scholarly journals A Closed-Loop Optimized System with CFD Data for Liquid Maldistribution Model

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1332
Author(s):  
Wei Zhang ◽  
Liyi Li ◽  
Baoping Zhang ◽  
Xin Xu ◽  
Jian Zhai ◽  
...  
Keyword(s):  
Closed Loop ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Structural Parameters ◽  
Computational Cost ◽  
Pso Algorithm ◽  
Oil Refining ◽  
Support Vector ◽  
Cfd Validation ◽  
Liquid Distributor

For the simulation of a trickle-bed reactor (TBR) in coal and oil refining, modeling the liquid maldistribution of the gas-liquid distributor incurs enormous pre-processing work and bears a huge computational cost. A closed-loop optimized system with computational fluid dynamic (CFD) data is therefore proposed for the first time in this paper. A fast prediction model based on support vector regression (SVR) is developed to simplify the modeling of the liquid flow rate in TBRs. The model uses CFD simulation results to determine an optimized set of structural parameters for the gas-liquid distributor in TBRs. In order to obtain an accurate SVR model quickly, the particle swarm optimization (PSO) algorithm is employed to optimize the SVR parameters. Then, the structural parameters corresponding to the minimum liquid maldistribution factor are calculated using the response surface methodology (RSM) based on the hybrid PSO-SVR model. The CFD validation results show a good agreement with the values predicted by RSM, with liquid maldistribution factors of 0.159 and 0.162, respectively.

scholarly journals Prediction of Crosswind Separation Velocity for Fan and Nacelle Systems Using Body Force Models: Part 1: Fan Body Force Model Generation without Detailed Stage Geometry

2019 ◽  
Vol 4 (4) ◽  
pp. 43 ◽  
Author(s):  
Quentin J. Minaker ◽  
Jeffrey J. Defoe
Keyword(s):  
Design Process ◽  
Body Force ◽  
Pressure Ratio ◽  
Computational Cost ◽  
The Body ◽  
Force Model ◽  
Limited Access ◽  
Turbofan Engines ◽  
Simplifying Assumptions ◽  
Dynamics Simulations

Modern aircraft engines must accommodate inflow distortions entering the engines as a consequence of modifying the size, shape, and placement of the engines and/or nacelle to increase propulsive efficiency and reduce aircraft weight and drag. It is important to be able to predict the interactions between the external flow and the fan early in the design process. This is challenging due to computational cost and limited access to detailed fan/engine geometry. In this, the first part of a two part paper, we present a design process that produces a fan gas path and body force model with performance representative of modern high bypass ratio turbofan engines. The target users are those with limited experience in turbomachinery design or limited access to fan geometry. We employ quasi-1D analysis and a series of simplifying assumptions to produce a gas path and the body force model inputs. Using a body force model of the fan enables steady computational fluid dynamics simulations to capture fan–distortion interaction. The approach is verified for the NASA Stage 67 transonic fan. An example of the design process is also included; the model generated is shown to meet the desired fan stagnation pressure ratio and thrust to within 1%.

Sign in / Sign up

Export Citation Format

Share Document