Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions最新文献

{"title":"Impact of Inlet Conditions on TVF Exit Flow Field","authors":"Mattia Graiff, Marian Staggl, Christian T. Wakelam, F. Heitmeir, E. Göttlich","doi":"10.1115/gt2022-80768","DOIUrl":"https://doi.org/10.1115/gt2022-80768","url":null,"abstract":"\u0000 The drive towards lightweight, more efficient engine architectures leads to the development and improvement of key aircraft engine components. The Turbine Vane Frame (TVF) can be seen as an evolution of the Turbine Center Frame (TCF), combining its structural and aerodynamic purposes with the function otherwise provided by the first stage turbine inlet guide vanes. Therefore, the TVF needs to smoothly guide the flow over the radial offset between high-pressure and low-pressure turbine stages, provide shrouded paths for oil lines, and impart to the flow the turning required by the following low pressure turbine stage. The expected beneficial effects on the engine include reduced weight, cost, and fuel burn. The key relevance of this component makes a broad, low-tier approach to its study highly desirable. The HighSpeed Wind Tunnel (HSWT) at the Technical University of Graz delivers excellent opportunities to explore the design space for Turbine Vane Frames. This paper deals with the impact of several important design parameters on the TVF. An engine relevant TVF configuration is replicated in an annular sector cascade test rig. The test rig is operated at relevant Mach number and turbulence level. Representative inlet flow is achieved through flow conditioning. Aerodynamic data is collected with five-hole probe and hot wire anemometry techniques. The insights offered by flow visualization and numerical computations are furthermore leveraged. Particular attention is given to the flow features at the TVF exit.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129508175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of a Distributed Element Roughness Model to Additively Manufactured Internal Cooling Channels","authors":"Samuel Altland, Xiang I. A. Yang, K. Thole, R. Kunz, S. McClain","doi":"10.1115/gt2022-81218","DOIUrl":"https://doi.org/10.1115/gt2022-81218","url":null,"abstract":"\u0000 Design for cooling effectiveness in internal flow systems relies on accurate models for dynamic losses and heat transfer. In these systems (e.g., gas turbine blades, intercoolers, heat exchangers), thousands of individual passages of varying configuration and roughness morphology can be present. In recent years, additive manufacturing (AM) has further expanded the design space, but can give rise to large-scale roughness features, whose sizes are comparable to the channel height. The range of roughness length scales in these systems makes CFD of the resolved rough surfaces impractical at a design level. Alternately, volumetric roughness modeling approaches, such as distributed element roughness models (DERM) can be leveraged, as they have computational costs orders of magnitude lower.\u0000 In this work, a DERM model based on the Double Averaged Navier-Stokes (DANS) equations is presented and applied to additively manufactured rough channels, representative of gas turbine blade cooling passages. Unique to this formulation of DERM is the specific treatment of the DERM drag coefficient and the spatially averaged Reynolds stresses. This generalized formulation of the drag coefficient allows for improved model accuracy across a wider array of potential roughness fields, without having to rely on calibration for each morphology. A novel two-layer approach to modeling the spatially averaged Reynolds stress is also proposed.\u0000 Three different AM rough surfaces documented by McClain et al. [1] were configured opposite smooth walls as well as each other to create a total of six channel configurations. Across the six cases, th roughness trough to peak size ranges from 0.15δ to 0.66δ, where δ is the channel half-width, and the roughness Reynolds number ranges from Rek = 60 to Rek = 300.\u0000 DERM predictions for spatially and temporally averaged mean flow quantities are compared to previously reported DNS results. Specifically, we observe good agreement in the mean velocity profiles, stress balances and drag partitions across the case matrix.\u0000 While DERM models are typically calibrated to specific deterministic roughness shape families at comparatively small roughness Reynolds numbers, these results demonstrate a wider range of applicability for the present, more generalized formulation. It is demonstrated that the proposed model can accommodate random roughness of large scale, typical of AM.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133662934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation Into Maximum Pressure Capability of Intershaft Hydraulic Seals","authors":"Achinie Warusevitane, K. Johnson, S. Ambrose","doi":"10.1115/gt2022-82196","DOIUrl":"https://doi.org/10.1115/gt2022-82196","url":null,"abstract":"\u0000 Hydraulic seals are used as intershaft seals in aero-engines and consist of an oil filled trough on the higher speed shaft and a fin on the lower speed shaft that dips into the oil forming the seal. Rotation is imparted to the sealing fluid within the trough and, similar to a manometer in operation the liquid either side of the fin can be at different heights allowing the seal to withstand differential pressure. In normal operation hydraulic seals do not leak air but if the differential pressure becomes too high the seal will break down and leakage will occur.\u0000 There is limited published research relating to hydraulic seals and the accuracy and reliability of the existing design approaches based on analytical derivations is not fully known. This acknowledged need to improve the ability to develop accurate computational models of hydraulic seals provides context for the current study.\u0000 An approach to evaluate the maximum pressure capacity of a hydraulic seal is therefore introduced in this work. Building on previously published studies, this paper presents results of a 2D numerical study into the performance of a simplified hydraulic seal geometry. This paper reports a numerical CFD methodology based on an axisymmetric Volume-of-Fluid (VOF) method. In this study there is no oil feed into the trough.\u0000 Results are presented for a range of shaft speeds of 2000–8000 rpm for the high speed shaft and 1000–4000 rpm for the low speed shaft. Fin position within the trough was varied. A criteria for broken seal was developed. The CFD data shows that the seal can withstand higher pressure at higher shaft speed with the characteristic following the expected linear relationship between differential pressure and shaft speed squared. The seal could withstand a higher differential pressure if the fin was closer to the housing on the high pressure side with this being attributed to the secondary air flow in the cavity.\u0000 The average core velocity was compared to values obtained using different analytical approaches and it was found that one where core angular velocity is proportional to the area averaged rotational velocities of the housing and fin was the best match to CFD data.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133672992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Verification of a Practical Engineering Design Method for Mixed-Flow Compressor Stages","authors":"Chenqing Zhang, Chenxi Zhao, Yonghong Tang, G. Xi","doi":"10.1115/gt2022-81969","DOIUrl":"https://doi.org/10.1115/gt2022-81969","url":null,"abstract":"\u0000 The mixed-flow compressor has high efficiency and pressurization ability even at an extremely high flow rate. However, so far the design principle of the mixed-flow compressor has not well been established. In this paper, a novel and practical design method of mixed flow impellers is developed, in which the meridional construction needs few control parameters, and easily applied to engineering product design.\u0000 In order to verify the developed method, a mixed-flow impeller with flow rate coefficient of 0.2374 is designed and manufactured for the experimental study. The experimental results show that the peak efficiency of the compressor at the machine Mach number of 0.6 and 0.8 reach 85.17% and 85.20%, respectively, which are competitively well-performed at large flow coefficient in the published literature. The comparison between experimental and numerical results verifies the feasibility and effectiveness of this proposed method and also provides some valuable guidance for the choice of the exit inclination angle of the mixed-flow impellers.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121170122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Numerical Study on the Effects of Circumferential Positions of Combustor Hot Streaks on a TCF Configuration","authors":"R. Benauer, S. Schreck, P. Leitl, Ena Badžek, M. Patinios, Federica Farisco","doi":"10.1115/gt2022-82419","DOIUrl":"https://doi.org/10.1115/gt2022-82419","url":null,"abstract":"\u0000 This work presents the results of numerical investigations conducted within the framework of a project focused on studying the influence of combustor hot streaks onto the aerodynamic performance of a TCF representative geometry. Different circumferential positions of the hot streaks, in respect to the leading edges of the high pressure turbine (HPT) stator vanes, were examined in order to determine changes in the flow field and its influence on the downstream components. Numerical investigations were carried out at Bionic Surface Technologies GmbH using the commercial tool ANSYS CFX. Transient simulations were performed to obtain the flow-field and capture the propagation of the hot streaks through the HPT stage into the TCF. Time averaged five-hole-probe measurements, taken from the TU Graz transonic test turbine facility (TTTF), were used as the initial boundary conditions for the simulations. Results are showing that the circumferential position of the hot streaks influences the temperature distribution at the TCF outlet since the hot streaks follow the fluid migration in the TCF, and are therefore affected by secondary flow structures originating from the fluid interaction with the HPT and TCF struts. Results also present an increase of pressure loss below 1%, for the hot streaks simulations.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122313079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acoustic Optimization Approach for Annular Diffusers in Turbomachinery Applications Using Plane Wave Modelling","authors":"Felix Fischer, J. Seume","doi":"10.1115/gt2022-80517","DOIUrl":"https://doi.org/10.1115/gt2022-80517","url":null,"abstract":"\u0000 The experimental investigation of unsteady aerodynamic effects in turbomachinery test rigs requires the establishment of anechoic boundary conditions in order to acquire data unaffected by acoustic reflections outside the test section. In this manner, controlled measurement environments can be achieved that allow for the acquisition of high-quality aeroacoustic and -elastic measurement data in turbomachinery test rigs. In the case of the initial design of the Aeroacoustic Wind Tunnel (AWT) at the Institute of Turbomachinery and Fluid Dynamics, acoustic reflections were observed in the diffuser section of the test rig, which interfered with the sound transmission measurements of low-pressure turbine airfoils.\u0000 The present paper describes a one-dimensional semi-analytical modelling and optimization approach of sound propagation in the AWTs diffuser section for plane waves based on Webster’s horn equation. With this approach, a new hub diffuser was designed for defined geometric and aerodynamic boundary conditions, which compared to the original geometry, reduce acoustic reflections due to continuous impedance matching. The design of a new supporting strut configuration further reduces reflections due to scattering from installations in the flow path. Validation of the modelling and solution approaches are carried out based on a comparison with experimental data of the initial (reference) design, as well as numerical simulations of both designs. According to analytical and numerical models the optimized design reduces acoustic reflections by up to 21.2 dB compared to the initial design.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131565581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploiting GPU-Based HPC Architectures to Accelerate an Unsteady CFD Solver for Turbomachinery Applications","authors":"F. Poli, M. Marconcini, R. Pacciani, D. Magarielli, E. Spano, A. Arnone","doi":"10.1115/gt2022-82569","DOIUrl":"https://doi.org/10.1115/gt2022-82569","url":null,"abstract":"\u0000 Aircraft engine designers are nowadays facing more and more challenges: they strive to reduce fuel consumption, obtain better engine performance, and create quieter, safer, and environmentally friendlier products. One of the key factors to achieve these goals is the availability of numerical simulation tools able to accurately predict engine behavior and of hardware/software platforms where the tools can successfully run.\u0000 However, accurate numerical simulations, particularly unsteady Computational Fluid Dynamics (CFD) ones based on sophisticated solvers, are time-consuming and demanding in terms of hardware resources. This may limit the industrial applicability of these methods.\u0000 A possible strategy to overcome this problem is the acceleration of numerical solvers on advanced High Performance Computing (HPC) architectures, in order to reduce the execution time down to values compatible with industrial needs.\u0000 Traf is a CFD solver for steady/unsteady three-dimensional Reynolds-averaged Navier-Stokes equations. It is developed at the University of Florence, with a special focus on turbomachinery applications. The current production release is a parallel code that runs on CPU-based platforms.\u0000 A new version of Traf has been ported to and optimized for GPU-based HPC architectures, in order to dramatically accelerate CFD analyses. The code has been tested on an industrial-grade use case concerning a low-pressure turbine module for aeronautical applications in the context of the EU H2020 funded project LEXIS (Large-Scale Execution for Industry & Society, GA 825532), comparing its performance with the CPU-based release and obtaining promising results. To this aim, the speedup weighted to account for the different hardware cost is selected as a meaningful Key Performance Indicator (KPI).","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121114372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and Simulation of the Cavitation Phenomenon in a Turbopump: A Multiphase Approach","authors":"Joris Cazé, Fabien Petitpas, E. Daniel, S. Le Martelot, Matthieu Queguineur","doi":"10.1115/gt2022-78025","DOIUrl":"https://doi.org/10.1115/gt2022-78025","url":null,"abstract":"\u0000 In this study, cryogenic flows in rocket engine that may undergo a phase change because of a loss of pressure in pump, or any depressurization process are considered. We proposed a well-posed mathematical representation for this kind of flow as well as the numerical model for seeking the solutions. The two important points addressed in this study are: the compressibility of the phases and the use of a rotating reference frame. The compressibility effects are quite essentials to obtain a physical and realistic cavitation model through the equation of state of the fluids (liquid and vapor), while the moving reference frame being the way we chose to model the pump motion.\u0000 The model we develop is based on conservation equations of mass, momentum and energy for each phase plus a non-conservative equation evolution for the volume fraction. The description of the flow is based on the diffuse interface method: the interfaces appear naturally in the flow (interfaces between vapor and liquid for example) and do not require any interface tracking method. The phase change process is based on a stiff relaxation procedure using thermodynamic equilibrium considerations.\u0000 Results related to a pump application are then presented using the open-source platform ECOGEN where the present numerical method is implemented. The model is able to produce a quite realistic pump characteristic curve where the relationship between the pump overpressure and its operating mass flow rate is expressed. In these first calculations it will be shown that cavitation may occur in some regions of the flow and that the multiphase approach is suited for this study.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121751525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Fidelity Simulation for Secondary Air System Seal Design in Aero Engines","authors":"A. Nasti, I. Voutchkov, David J. J. Toal, A. Keane","doi":"10.1115/gt2022-80391","DOIUrl":"https://doi.org/10.1115/gt2022-80391","url":null,"abstract":"\u0000 Secondary air system seals in aero engines sit at the intersection between all the major aspects of the physics of the system. Their behavior is affected by the air system, the thermal physics, the effect of flight loads and is highly dependent on the engine component movements, the operating conditions, and the supporting hardware. Due to the number of functional and physical interfaces in the engine, seal design is therefore a highly coupled multi-physics problem and requires multiple iterations during the design process to converge to a solution that meets system requirements and optimizes engine specific fuel consumption.\u0000 At different stages of the design process, simulation models with different levels of fidelity can be built. Due to the long runtimes of high-fidelity coupled multi-disciplinary models and to the iterative nature of the process, seal design in industry presents significant computational cost challenges, in particular in the phases of the design that require multiple simulation runs.\u0000 Multi-fidelity computational techniques for surrogate modelling and optimization such as Kriging and co-Kriging have been demonstrated on a number of industrial applications and have the potential to significantly reduce the number of function evaluations for computationally expensive optimization problems, improve the accuracy of the predictions of surrogate models and allow the development of improved simulation strategies for a specific product design.\u0000 This paper demonstrates the use of multi-fidelity simulation techniques on aero engine secondary air system seal design and shows how these techniques can be used in the context of system, sub-system and component design. This is achieved by combining results from a simple two-dimensional Finite Element Analysis with those from a coupled secondary air system-thermomechanical model.\u0000 Depending on the stage of the design process and on the specific design decisions being made, the use of computational power in simulation often comes down to a trade-off between reduced overall computational time and improved result accuracy. Multi-fidelity simulation frameworks provide the environment to drive holistic choices on the simulation strategy, reducing the cost of the design and offering agility in the industrial response to market changes or new technologies. Moreover, this methodology establishes an infrastructure for updating the virtual product at each step of the product lifecycle, allowing experimental or service data to feed the system-level simulation models to produce a digital twin.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133151740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}