Abstract This manuscript presents Computational Fluid Dynamics simulation of a ramjet combustor using Reynolds Averaged Navier–Stokes approach for turbulence with flamelet combustion modelling. In the approach a one-dimensional premixed flame simulation is performed to cover a wide range of mixture fraction space. After a mesh study, effects of turbulence, Realizable k - ε and SST k - ω , and combustion modelling, Steady Laminar Flamelet and Flamelet Generated Manifold, are investigated in detail. The Flamelet Generated Manifold model that offers a reaction delay by employing an additional progress variable, shows there are no reactions taking place in the vicinity of jet inlets, hence the unrealistic temperature rise that is seen in the case of using Steady Laminar Flamelet is not observed. A study on the choice of progress variable based on the combustion products is carried out. The present study readily demonstrates good predictability of Flamelet Generated Manifold combustion modelling in such a dual inlet ramjet combustion chamber.
摘要:本文采用雷诺平均纳维-斯托克斯方法对冲压发动机燃烧室湍流流场进行了计算流体动力学模拟。在该方法中，一维预混火焰模拟覆盖了大范围的混合分数空间。在网格研究的基础上，详细研究了湍流的影响，Realizable k - ε和SST k - ω，以及燃烧模型，稳定层流小火焰和小火焰生成流形。Flamelet生成歧管模型通过使用额外的进度变量来提供反应延迟，表明在喷气入口附近没有发生反应，因此在使用Steady Laminar Flamelet的情况下看不到不切实际的温度上升。对基于燃烧产物的进度变量选择进行了研究。本研究很好地证明了在这种双入口冲压发动机燃烧室中火焰生成歧管燃烧模型的良好可预测性。
{"title":"Effects of turbulence and flamelet combustion modelling on the CFD simulation of a dual inlet ramjet combustor","authors":"Mehmet Burak Solmaz, Sitki Uslu","doi":"10.1515/tjj-2023-0039","DOIUrl":"https://doi.org/10.1515/tjj-2023-0039","url":null,"abstract":"Abstract This manuscript presents Computational Fluid Dynamics simulation of a ramjet combustor using Reynolds Averaged Navier–Stokes approach for turbulence with flamelet combustion modelling. In the approach a one-dimensional premixed flame simulation is performed to cover a wide range of mixture fraction space. After a mesh study, effects of turbulence, Realizable k - ε and SST k - ω , and combustion modelling, Steady Laminar Flamelet and Flamelet Generated Manifold, are investigated in detail. The Flamelet Generated Manifold model that offers a reaction delay by employing an additional progress variable, shows there are no reactions taking place in the vicinity of jet inlets, hence the unrealistic temperature rise that is seen in the case of using Steady Laminar Flamelet is not observed. A study on the choice of progress variable based on the combustion products is carried out. The present study readily demonstrates good predictability of Flamelet Generated Manifold combustion modelling in such a dual inlet ramjet combustion chamber.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135830441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andriy A. Avramenko, N. P. Dmitrenko, I. V. Shevchuk
Abstract The article presents the results of an analytical study of the flow dynamics in a microdiffuser. An expression for the velocity profile is obtained with account for slip effects. The effect of the Knudsen number on the velocity profiles is shown. The effect of the microdiffuser angle on the flow velocity profile and the friction coefficient is analyzed. The opening angle of the microdiffuser was determined, at which slip effects do not affect the velocity profile.
{"title":"Fluid flow in a microdiffuser at small Reynolds numbers","authors":"Andriy A. Avramenko, N. P. Dmitrenko, I. V. Shevchuk","doi":"10.1515/tjj-2023-0008","DOIUrl":"https://doi.org/10.1515/tjj-2023-0008","url":null,"abstract":"Abstract The article presents the results of an analytical study of the flow dynamics in a microdiffuser. An expression for the velocity profile is obtained with account for slip effects. The effect of the Knudsen number on the velocity profiles is shown. The effect of the microdiffuser angle on the flow velocity profile and the friction coefficient is analyzed. The opening angle of the microdiffuser was determined, at which slip effects do not affect the velocity profile.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42558297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In order to realize the most economical operation of helicopter power system, the optimal rotor speed control method is proposed and designed. Firstly, the simplified performance calculation model of helicopter required power and turboshaft engine are established, which constitute the performance calculation model of helicopter power system together. Then, according to the above model, through applying blade loading constraint and selecting the minimum engine fuel flow as the optimization objective, an integrated optimization method of optimal rotor speed based on golden section method is proposed, which reveals the variation law of optimal rotor speed under different operation conditions. Finally, the numerical simulation and hardware-in-loop (HIL) simulation are conducted separately to validate the optimal rotor speed control method. The results indicate that compared with constant rotor speed operation, optimal rotor speed control method can decrease engine fuel flow by more than 21 %, which proves the significant effectiveness and satisfactory feasibility. The optimal rotor speed control method ensures that the helicopter power system operates at the optimal rotor speed, and is beneficial to reach the most economical cruise target.
{"title":"A study on optimal rotor speed control method for helicopter power system considering the influence of infrared suppressors","authors":"Zhaoguang Wang, Jiatong Du, Haoran Guo","doi":"10.1515/tjj-2023-0048","DOIUrl":"https://doi.org/10.1515/tjj-2023-0048","url":null,"abstract":"Abstract In order to realize the most economical operation of helicopter power system, the optimal rotor speed control method is proposed and designed. Firstly, the simplified performance calculation model of helicopter required power and turboshaft engine are established, which constitute the performance calculation model of helicopter power system together. Then, according to the above model, through applying blade loading constraint and selecting the minimum engine fuel flow as the optimization objective, an integrated optimization method of optimal rotor speed based on golden section method is proposed, which reveals the variation law of optimal rotor speed under different operation conditions. Finally, the numerical simulation and hardware-in-loop (HIL) simulation are conducted separately to validate the optimal rotor speed control method. The results indicate that compared with constant rotor speed operation, optimal rotor speed control method can decrease engine fuel flow by more than 21 %, which proves the significant effectiveness and satisfactory feasibility. The optimal rotor speed control method ensures that the helicopter power system operates at the optimal rotor speed, and is beneficial to reach the most economical cruise target.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42994121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenhuan Tang, X. Chen, Hailun Zhou, Yu Lu, Hongbin He
Abstract In order to explore the air ingestion characteristics of the open-ends squeeze film dampers (SFD), a 3D computational fluid dynamics solution model of the SFD was proposed based. The setting of opening boundary conditions was considered, which was verified experimentally by the bidirectional excitation. The results revealed that with the same precession frequency, the smaller radial clearance leads to the greater oil film damping. An increasing oil supply and oil holes led to the smaller air ingestion range at the end. The design guideline for the open-ends SFD was investigated in the present work.
{"title":"Dynamic characteristics of open-ends squeeze film dampers with air ingestion","authors":"Zhenhuan Tang, X. Chen, Hailun Zhou, Yu Lu, Hongbin He","doi":"10.1515/tjj-2023-0032","DOIUrl":"https://doi.org/10.1515/tjj-2023-0032","url":null,"abstract":"Abstract In order to explore the air ingestion characteristics of the open-ends squeeze film dampers (SFD), a 3D computational fluid dynamics solution model of the SFD was proposed based. The setting of opening boundary conditions was considered, which was verified experimentally by the bidirectional excitation. The results revealed that with the same precession frequency, the smaller radial clearance leads to the greater oil film damping. An increasing oil supply and oil holes led to the smaller air ingestion range at the end. The design guideline for the open-ends SFD was investigated in the present work.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47515299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract As turbine operating conditions change, the blade height and tip clearance undergo continuous alterations due to the combined effects of thermal stress, aerodynamic forces and centrifugal forces, subsequently influencing the turbine performance. To take this effect into account in turbine performance prediction, this study considers the influence of fluid-heat-structure coupling on blade height and tip clearance and establishes a one-dimensional comprehensive prediction method for multi-stage axial turbine performance considering blade height. When compared with experimental results from a four-stage axial turbine, by considering the fluid-thermal-solid coupling effects, the average relative error in total pressure ratio prediction is reduced from 3.76 % to 1.99 % and the average relative error in total temperature ratio prediction is reduced from 2.03 % to 1.26 %. Compared with the traditional flow prediction method, the prediction results of turbine characteristics considering blade height and tip clearance changes in this paper are closer to the experimental results.
{"title":"Study on one-dimensional performance prediction of multi-stage axial turbine based on the blade height","authors":"Kefang Xu, Ze Yuan, Zhaojun Li, G. Yue","doi":"10.1515/tjj-2023-0058","DOIUrl":"https://doi.org/10.1515/tjj-2023-0058","url":null,"abstract":"Abstract As turbine operating conditions change, the blade height and tip clearance undergo continuous alterations due to the combined effects of thermal stress, aerodynamic forces and centrifugal forces, subsequently influencing the turbine performance. To take this effect into account in turbine performance prediction, this study considers the influence of fluid-heat-structure coupling on blade height and tip clearance and establishes a one-dimensional comprehensive prediction method for multi-stage axial turbine performance considering blade height. When compared with experimental results from a four-stage axial turbine, by considering the fluid-thermal-solid coupling effects, the average relative error in total pressure ratio prediction is reduced from 3.76 % to 1.99 % and the average relative error in total temperature ratio prediction is reduced from 2.03 % to 1.26 %. Compared with the traditional flow prediction method, the prediction results of turbine characteristics considering blade height and tip clearance changes in this paper are closer to the experimental results.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48196291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract There are developed methods for high-pressure turbine (HPT) blade loads and remaining useful life (RUL) prediction; however, they are ineffective and time-consuming for in-service HPT blades under actual operating conditions. Hence, it is necessary to use an acceptable computational effort to predict the HPT blade’s load and in-service lifetime. Drawing from the idea of the usage-based life (UBL) prediction method, this paper first proposes a framework for the life digital twin (LDT) to characterize and track the in-service life consumption of the HPT blades under actual operating conditions. The second work mainly focuses on developing the steady-state and transient load calculation surrogate models for the HPT blade’s LDT. Using the developed surrogate models, it can now calculate the steady-state and transient loads of the HPT blade in an acceptable time with the necessary accuracy. The proposed approach is demonstrated on an HPT blade of a typical commercial turbofan engine. Because the operating load of the HPT blade severely affects its in-service lifetime, the application of this approach enables the construction of an LDT of the HPT blade. It can reduce the uncertainty and variability associated with the in-service life prediction of the HPT blade under actual operating conditions.
{"title":"In-service load calculation surrogate models for high-pressure turbine blade life digital twin","authors":"Chunhua Li, Jianzhong Sun, Bowen Wang, Jinchen Nian","doi":"10.1515/tjj-2023-0040","DOIUrl":"https://doi.org/10.1515/tjj-2023-0040","url":null,"abstract":"Abstract There are developed methods for high-pressure turbine (HPT) blade loads and remaining useful life (RUL) prediction; however, they are ineffective and time-consuming for in-service HPT blades under actual operating conditions. Hence, it is necessary to use an acceptable computational effort to predict the HPT blade’s load and in-service lifetime. Drawing from the idea of the usage-based life (UBL) prediction method, this paper first proposes a framework for the life digital twin (LDT) to characterize and track the in-service life consumption of the HPT blades under actual operating conditions. The second work mainly focuses on developing the steady-state and transient load calculation surrogate models for the HPT blade’s LDT. Using the developed surrogate models, it can now calculate the steady-state and transient loads of the HPT blade in an acceptable time with the necessary accuracy. The proposed approach is demonstrated on an HPT blade of a typical commercial turbofan engine. Because the operating load of the HPT blade severely affects its in-service lifetime, the application of this approach enables the construction of an LDT of the HPT blade. It can reduce the uncertainty and variability associated with the in-service life prediction of the HPT blade under actual operating conditions.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49595165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This paper presents the numerical analysis of a convergent-divergent circular nozzle with the exit Mach number of 1.69 with and without passive control at the exit. The passive control method opted for this analysis was inward and outward ascending triangular protrusion. This paper explores the influence of the passive control geometry and its blockage area concerning the nozzle exit. The nozzle pressure ratio (NPR) used for carrying out the flow analysis were 3, 4.932, and 6. Two different inward and outward protrusions were used with a height of 1.5 mm and 3 mm. From the results, the potential core length of the protrusion 1.5 mm height was not much changed in the both outward and inward cases. But when the height of the protrusion was increased to 3 mm, there was a noticeable core length reduction at all NPR but with different cases. At the NPR of 6, the potential core length of the inward protrusions 3 mm was reduced by 44 % compared to the plain CD nozzle.
{"title":"Numerical analysis on the effect of passive control geometry in supersonic jet mixing enhancement","authors":"N. Subramani, S. M, Gowtham Gajapathy","doi":"10.1515/tjj-2023-0068","DOIUrl":"https://doi.org/10.1515/tjj-2023-0068","url":null,"abstract":"Abstract This paper presents the numerical analysis of a convergent-divergent circular nozzle with the exit Mach number of 1.69 with and without passive control at the exit. The passive control method opted for this analysis was inward and outward ascending triangular protrusion. This paper explores the influence of the passive control geometry and its blockage area concerning the nozzle exit. The nozzle pressure ratio (NPR) used for carrying out the flow analysis were 3, 4.932, and 6. Two different inward and outward protrusions were used with a height of 1.5 mm and 3 mm. From the results, the potential core length of the protrusion 1.5 mm height was not much changed in the both outward and inward cases. But when the height of the protrusion was increased to 3 mm, there was a noticeable core length reduction at all NPR but with different cases. At the NPR of 6, the potential core length of the inward protrusions 3 mm was reduced by 44 % compared to the plain CD nozzle.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48515732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Jeyakumar, Akash Shrikant Patale, Prince Sharma
Abstract The flow performance of a dual wall-mounted cavity in a strut-injector scramjet combustor in steady reacting flow conditions is computationally analyzed. A baseline configuration corresponding to DLR experiments and two proposed configurations with varying bottom wall cavity depth and fixed top wall ramp is considered. Steady-flow computations are performed using the 2-D Reynolds Averaged Navier–Stokes method with k-ω SST turbulence closure coupled and single-step reaction chemistry. The calculated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. The cavity and strut are mounted downstream of the strut to analyze the shock patterns and their interference with the shear layer mixing features. The estimated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. Incorporating cavity and ramp configuration provides earlier complete combustion compared to the baseline model, with a marginal rise in the total pressure caused by additional shock wave formation that emanates from the corners of the cavity and ramp. The combustion zone widens in the lateral direction as the cavity shifts the shock train downstream of the strut injector owing to intense shock shear layer interactions.
{"title":"Impact of cavity and ramp configuration on the combustion performance of a strut-based scramjet combustor","authors":"S. Jeyakumar, Akash Shrikant Patale, Prince Sharma","doi":"10.1515/tjj-2023-0067","DOIUrl":"https://doi.org/10.1515/tjj-2023-0067","url":null,"abstract":"Abstract The flow performance of a dual wall-mounted cavity in a strut-injector scramjet combustor in steady reacting flow conditions is computationally analyzed. A baseline configuration corresponding to DLR experiments and two proposed configurations with varying bottom wall cavity depth and fixed top wall ramp is considered. Steady-flow computations are performed using the 2-D Reynolds Averaged Navier–Stokes method with k-ω SST turbulence closure coupled and single-step reaction chemistry. The calculated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. The cavity and strut are mounted downstream of the strut to analyze the shock patterns and their interference with the shear layer mixing features. The estimated flow patterns, density, pressure, and temperature fields are compared with shadowgraph and wall pressure measurements from DLR experiments. Incorporating cavity and ramp configuration provides earlier complete combustion compared to the baseline model, with a marginal rise in the total pressure caused by additional shock wave formation that emanates from the corners of the cavity and ramp. The combustion zone widens in the lateral direction as the cavity shifts the shock train downstream of the strut injector owing to intense shock shear layer interactions.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49542980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Understanding the occurrence of various feedback mechanisms of an under-expanded impinging supersonic jet is a crucial task in research. The presence of several jet modes is examined in this study for the flat and corrugated impinging plate geometries. The behavior of impinging plate configurations during mode switching is investigated by varying the flow state, such as the jet Mach number. The staging behavior at various jet Mach numbers is observed using acoustic spectral plots and schlieren flow visualization. To explore the presence of various types of modes during the jet impingement due to the modification of jet Mach number, ensemble averaging and Proper Orthogonal Decomposition of schlieren images are carried out. In the majority of situations, the corrugated design shows a reduction in tonal noise and overall sound pressure level. In exceptional cases, for the corrugated plates, the enhanced overall sound pressure level is caused by the existence of axisymmetric instability (A1, A2).
{"title":"Proper Orthogonal Decomposition analysis of mode switching in supersonic jets impinging on flat and corrugated plates","authors":"D. Sarangi, Ramanujam Karthik, K. Srinivasan","doi":"10.1515/tjj-2023-0071","DOIUrl":"https://doi.org/10.1515/tjj-2023-0071","url":null,"abstract":"Abstract Understanding the occurrence of various feedback mechanisms of an under-expanded impinging supersonic jet is a crucial task in research. The presence of several jet modes is examined in this study for the flat and corrugated impinging plate geometries. The behavior of impinging plate configurations during mode switching is investigated by varying the flow state, such as the jet Mach number. The staging behavior at various jet Mach numbers is observed using acoustic spectral plots and schlieren flow visualization. To explore the presence of various types of modes during the jet impingement due to the modification of jet Mach number, ensemble averaging and Proper Orthogonal Decomposition of schlieren images are carried out. In the majority of situations, the corrugated design shows a reduction in tonal noise and overall sound pressure level. In exceptional cases, for the corrugated plates, the enhanced overall sound pressure level is caused by the existence of axisymmetric instability (A1, A2).","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44904841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In variable geometry turbine vanes, tip clearance height and shape vary with the rotation of the vane, which affect the aerodynamic performance significantly. However, these issues are rarely considered in published studies. The current paper investigated the flow field features of transonic variable geometry turbine vanes with non-uniform partial clearance induced by the vane rotating. The results show that: The influence of guide vane rotation on the clearance height and its distribution cannot be ignored. At the same turning angle, the maximum clearance difference is up to 0.79 mm (0.8 % vane height). The height and shape variation of the non-uniform clearance leads to the change in the leakage flow rate, secondary flow structure, and aerodynamic loss of the variable guide vane. Under the combined effect of pressure difference on both sides of the clearance, axial and circumferential non-uniformity of clearance height, the total pressure loss coefficient is up to 9.44 % when the turning angle is −10°. The effect of the pivot on the clearance flow was also analyzed. The pivot increases the pressure in the gap flow field and reduces leakage flow velocity. However, a backflow region appears at the suction side of the pivot, which increases the aerodynamic losses.
{"title":"Numerical investigation of tip clearance flow in a variable geometry turbine with non-uniform partial clearance","authors":"Yueqi Liu, Shaowen Chen, S. Wang","doi":"10.1515/tjj-2023-0063","DOIUrl":"https://doi.org/10.1515/tjj-2023-0063","url":null,"abstract":"Abstract In variable geometry turbine vanes, tip clearance height and shape vary with the rotation of the vane, which affect the aerodynamic performance significantly. However, these issues are rarely considered in published studies. The current paper investigated the flow field features of transonic variable geometry turbine vanes with non-uniform partial clearance induced by the vane rotating. The results show that: The influence of guide vane rotation on the clearance height and its distribution cannot be ignored. At the same turning angle, the maximum clearance difference is up to 0.79 mm (0.8 % vane height). The height and shape variation of the non-uniform clearance leads to the change in the leakage flow rate, secondary flow structure, and aerodynamic loss of the variable guide vane. Under the combined effect of pressure difference on both sides of the clearance, axial and circumferential non-uniformity of clearance height, the total pressure loss coefficient is up to 9.44 % when the turning angle is −10°. The effect of the pivot on the clearance flow was also analyzed. The pivot increases the pressure in the gap flow field and reduces leakage flow velocity. However, a backflow region appears at the suction side of the pivot, which increases the aerodynamic losses.","PeriodicalId":50284,"journal":{"name":"International Journal of Turbo & Jet-Engines","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46637710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：