Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines最新文献

{"title":"Experimental and Numerical Investigations of Steam Turbine Exhaust Hood Flow Field With Two Types of Diffusers","authors":"S. Tabata, H. Fukushima, K. Segawa, K. Ishibashi, Yoshihiro Kuwamura, H. Sugishita","doi":"10.1115/gt2019-90640","DOIUrl":"https://doi.org/10.1115/gt2019-90640","url":null,"abstract":"\u0000 The exhaust hood performance of LP turbine plays an important role in the efficiency of steam turbine. By improving the exhaust performance, the kinetic energy of the last stage rotating blades can be converted to the potential energy and it becomes possible to improve the turbine efficiency. However, the flow field in the diffuser is closely related to the flow pattern of the last stage rotating blade, and the flow field inside the exhaust chamber afterward has a complicated three dimensional flow field. Therefore, in this study, it conducted a scaled model steam turbine test using two types of diffusers and CFD, and evaluated exhaust performance and flow pattern.\u0000 The verification test was carried out using a test turbine (4 stages) of × 0.33 scale, the velocity field and the pressure field were evaluated by traverse and the wall pressure measurements.\u0000 The corresponding CFD was calculated by ANSYS CFX. All four stages of blades and seals, exhaust chambers were accurately modeled. Due to the detailed CFD, the internal flow of the exhaust chamber exhibiting complicated three-dimensionality was visualized and the flow pattern was evaluated.\u0000 The verification test results and the corresponding CFD results were compared and evaluated, and it has been found that the overall performance predicted by CFD is well showing the verification test result. Therefore, it has been found that CFD can help to understand the internal flow of the exhaust chamber exhibiting complex three-dimensional characteristics.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123761725","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":"Design of High Specific Speed Mixed Flow Micro-Compressor for Co-Flow Jet Actuators","authors":"Kewei Xu, Gecheng Zha","doi":"10.1115/gt2019-90980","DOIUrl":"https://doi.org/10.1115/gt2019-90980","url":null,"abstract":"\u0000 This paper conducts aerodynamic design of a high specific speed mixed flow micro-compressor used as an actuator for Co-flow Jet (CFJ) Active Flow Control (AFC) airfoil. The aerodynamic design poses several challenges, including: 1) Small size with very low Reynolds number; 2) High specific speed for mixed-flow compressor due to high mass flow rate and low total pressure ratio; 3) Static pressure ratio lower than 1 to match the low pressure of CFJ airfoil leading edge (LE) suction peak.\u0000 The numerical design approach is validated with a mixed flow micro-compressor with very good agreement between the predicted performance and the measured data. Front loaded rotor blade work distribution is adopted to decrease boundary layer loss at the blade surface. Free vortex work distribution is applied for the rotor span to reduce spanwise mixing loss. The rotor efficiency achieved by the numerical prediction is 91.7%. Significant loss is observed downstream of the rotor when the flow reaches the stator and the outlet guide vane (OGV). For the stator, it is found that an inlet and outlet flow path area ratio of 1.05 achieves a very high total pressure recovery of 99.29%. A very good stage isentropic efficiency of 84.3% is achieved. The final design of micro-compressor achieves a flow coefficient of 0.3 at the design point with a total pressure ratio of 1.117 and a static pressure ratio of 0.987. A structure FEM analysis indicates that the rotor blades satisfy the structure strength and modal frequency requirement.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"94 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114103894","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":"Separation of Water Film From Last Stage Guide Blades of 1000 MW Steam Turbine","authors":"M. Hoznedl, L. Tajč, L. Bednář, A. Macálka, A. Z̆ivný","doi":"10.1115/gt2019-90221","DOIUrl":"https://doi.org/10.1115/gt2019-90221","url":null,"abstract":"\u0000 The paper deals with experimental research of water and steam flow through the grooves in hollow stator blades of the steam turbine last stages with the support of CFD calculations. Also the amount of water sucked by the circumferential groove in the upper limiting wall between the last stage rotor and stator blade was experimentally measured.\u0000 Measuring took place on a steam turbine with nominal output 1000 MW. With gradual increase of the turbine output it was possible to measure parameters of hollow blades suction for outputs 205, 460, 730, 870 and also 1006 MW.\u0000 Before starting turbine a complex measuring system was installed consisting of cyclone separator, set of measuring tanks, orifice and pressure sensors and transducers. This measuring system was connected to one hollow stator blade near the horizontal joint. After the measurement the extraction of steam water mixture from this blade was transferred to the condenser via the diffuser chamber in the same way as other non-measured blades.\u0000 Based on measured data, i.e. the pressure in the hollow stator blade and the flow rate of water captured by the hollow stator blade, it is possible to define the efficiency of suction tract from the viewpoint of total wetness in the inter-stage channel and from the viewpoint of rough liquid phase. The rough liquid phase means water films that flow near the draining grooves and sucked inside to the grooves.\u0000 The main part of the submitted paper is an analysis of the measured data. Among the analysis results are, besides the flows of rough water phase along the blade surface, the above mentioned efficiency of total wetness suction and of water film suction. For the needs of the analysis there are certain input data, e.g. the value of static pressure and wetness on the blade surface close to the slots that must be defined theoretically using flow path calculations or using CFD methods. In this case, in order to obtain input data, CFD simulations were used when the whole last stage was calculated with the diffuser and exhaust hood. Boundary conditions for CFD were taken from experimental measurements that took place simultaneously with measurement of separated water phase. Numerical simulations were not running for all outputs, but only for three of them — 460, 730 and 1006 MW. For this reason there are no sufficient data for CFD calculations for all outputs and input data of other cases had to be extracted and, based on experience, extrapolated.\u0000 On the circumferential groove only a part of 30 mm of length was measured, again near the horizontal joint. Due to a short measured groove length it was not possible to obtain the water flow data which would describe suction properties for the whole circumference.\u0000 The results of experimental measurements provide very important information about the whole suction tract behaviour and its ability to remove liquid water films from the stator blades surface. As very good qualities of the suction tract were confirmed ","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"483 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133010000","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":"Effects of Labyrinth Fin Wear on Aerodynamic Performance of Turbine Stages: Part I — Bending Damages","authors":"Xinbo Dai, Xin Yan","doi":"10.1115/gt2019-90152","DOIUrl":"https://doi.org/10.1115/gt2019-90152","url":null,"abstract":"\u0000 Labyrinth seals are widely applied in turbo machines because of their geometrical simplicity, convenient installation, reliable operation and excellent sealing performance. However, in realistic operation process, they usually encounter transient conditions (starting-up, shutting down, etc.) and unavoidable vibrations, which may cause wear in the labyrinth fins. After rubbing, the sealing performance of labyrinth seal will be varied in contrast to the original design. Correspondingly, the aerodynamic efficiency of the turbine stage will be affected by the variation of leakage flow in rubbing process. However, in published literature with respect to the labyrinth seal wear, most of the attention has been paid on revealing sealing performance degradation of labyrinth seal itself. Few studies have been concentrated on the influence of labyrinth seal wear on aerodynamic performance of turbine stages. In such background, the present paper utilizes the numerical methods to investigate the effects of labyrinth seal bending damages on aerodynamic performance of turbine stages. Firstly, under several assumptions, the bending geometrical model was established to describe different degrees of bending damages. Secondly, using three-dimensional RANS simulations, the effects of effective clearance variation due to bending on leakage flow and flow fields in turbine stages were investigated. The overall performance of the turbine stages with teeth-bending damages was also compared with the original design case. The influence of the forward bending and backward bending of labyrinth seals were analyzed and compared with each other. The total-total isentropic efficiency of turbine stages, leakage rates, outlet flow angles, reaction degrees and profile static pressure distributions, entropic distributions and flow fields in seals were obtained and compared to the original design case. The results indicate that the leakage rates in the worn labyrinth seal are quite relevant to the effective clearance, especially for the backward bending damages. As the effective clearances in backward bending cases are increased by 0.2–0.6mm, the isentropic efficiency of turbine stages is decreased by about 1–2%. However, for the forward bending damages, the aerodynamic performance and leakage rates in turbine stages are not sensitive to the effective clearance.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128713913","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":"Study on Analytical Method for Thermal and Flow Field of a Turbocharger With the Catalyst Unit","authors":"T. Kitamura, S. Ibaraki, Y. Kihara, T. Hoshi, M. Ebisu","doi":"10.1115/gt2019-90451","DOIUrl":"https://doi.org/10.1115/gt2019-90451","url":null,"abstract":"\u0000 The analytical and experimental study on thermal and flow field of a turbocharger with the catalyst unit has been conducted for the thermal management at the downstream side of turbochargers, which have crucial effects on activation of catalyst units.\u0000 CHT (Conjugate Heat Transfer) calculations, working for simulating heat transfer with mutual dependence between solid structures and fluid, are applied to the turbocharger including the turbine section, the bearing housing and the catalyst unit to acquire the whole of thermal and flow field accurately. The modeling for catalyst element has also been developed.\u0000 In addition, the gas stand test demonstrated turbochargers under cold start-up condition to validate CHT calculations. Analytical results are evaluated against experimental data. Eventually, the proposed analytical method has been proved to have the advantage of designing for heating catalyst units.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131322609","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":"Investigation on Unsteady and Steady Swirling Inflow Effect on Turbocharger Turbine Performance","authors":"Z. Ding, W. Zhuge, Yangjun Zhang, Chen Yingjie, Chang Liu","doi":"10.1115/gt2019-91155","DOIUrl":"https://doi.org/10.1115/gt2019-91155","url":null,"abstract":"\u0000 Turbocharger has experienced a prompt expansion in vehicle industry in recent years, because it enables downsizing of internal combustion engines (ICEs) so as to cutting down CO2 emissions. Turbocharger turbine efficiency is vital for the performance and emission of ICEs. Conventionally, turbines are designed and optimized under steady and uniform inflow conditions, but they are always fed with pulsating and swirling inflow on ICEs. Understanding turbine behaviors under enginelike unsteady swirling inflow conditions is significant to improve turbine on-engine performance.\u0000 The purpose of the present study is to examine and compare the unsteady and steady swirling inflow effect on turbocharger turbine performance. The investigation reveals that the turbine suffers substantial efficiency reductions under swirling inflow conditions, no matter under unsteady or steady state, and the efficiency reductions are related with the intensity of inlet swirls. The unsteady and steady swirling inflow leads to reductions in both the absolute and relative flow angles. The swirling inflow results in different effect on turbine performance under unsteady state from steady state. Time lags exist between the unsteady swirling inflow affect the turbine performance. Besides, unsteady swirling inflow effect lead to fluctuations of turbine performance parameters, which discloses a coupled effect of the unsteady and swirling inflow. The unsteady effect and the swirling inflow effect do not simply superpose with each other, but have complicated interactions with each other. Both pulsating and swirling inflow can lead to circumferential flow distortions at rotor inlet by themselves, and when turbine is fed with both pulsatile and swirling inflow together the circumferential flow distortion would be result of their synergetic effect.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126887268","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":"Aspects of Creep Fatigue Lifetime Assessment for High Temperature Components With Accumulative Model","authors":"S. Linn, C. Kontermann, M. Oechsner","doi":"10.1115/gt2019-90909","DOIUrl":"https://doi.org/10.1115/gt2019-90909","url":null,"abstract":"\u0000 Alternating temperatures induce thermomechanical stresses in thick-walled components such as turbine rotors or housings, which can lead to fatigue and superimposed creep. Subsequently, damage can occur at their heated surfaces. Under the nowadays prevailing operating conditions of power plants with multiple cold, warm and hot starts as reaction to the high volatility of electric demand from fossil fired power plants for ensuring grid stability, methods for lifetime assessment are coming more into the focus of investigations and research. Engineers are trying to estimate the residual lifetimes of in-service components and operators of power plants ask for strategies to minimize the calculative material damage while simultaneously providing a maximum flexibility with shortest response times on altered demands. Among constitutive models, which are not subject of this paper, accumulative models for lifetime assessment were introduced several decades ago and are partially considered in applicable standards. Such models based on a damage accumulation are easy to apply but they are considered to be either very imprecise or very conservative, while the conservatism reflects the necessity of large safety margins.\u0000 This paper summarize a few measures, which are suitable to improve the predictive quality of models based on a simple time-fraction rule. The proposed model is based on a synthesis of hysteresis loops for isothermal and non-isothermal conditions, concepts for consideration of cyclic softening or hardening during lifetime, concepts for dealing with internal back stresses, mean strains or stresses, and for accounting of creep-fatigue interaction. The latter is based on a so-called transition time concept, where the creep damage during dwell times partially attributes to the portion of fatigue damage, which in turn is determined from fatigue life curves for dwell time experiments. In addition, the model comprises a concept for the post-processing of transient FEM calculations and dealing with multiaxial loading conditions.\u0000 Since the essentials of the proposed method with the transition time concept were published more than 10 years ago, the listed modifications improve the benefit for daily engineering usage. Validation experiments provide evidence of the models predicting capabilities with acceptable uncertainty.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128768767","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":"Advanced Steam Turbine Technology for Unique Double Reheat Steam Power Plant Layout","authors":"Benjamin Kloss-Grote, M. Wechsung, R. Quinkertz, Henning Almstedt","doi":"10.1115/gt2019-90934","DOIUrl":"https://doi.org/10.1115/gt2019-90934","url":null,"abstract":"\u0000 Environmental aspects have increased the pressure on the fossil power generation industry to reduce carbon dioxide (CO2) emissions. One way to achieve this is by increasing the overall plant efficiency, which also fosters an economical plant operation. How can the efficiency of a next generation coal fired ultra super critical (USC) steam power plant (SPP) be increased significantly in the nearest future while maintaining its familiar reliability and availability at the same time? In China’s national USC SPP demonstration project, Pingshan Phase II, this challenge is met by a double reheat cross compound turboset with one elevated and one conventional turbine layout, together with increased steam parameters of up to 325 bar and steam temperatures of up to 630°C. The nominal electrical capacity of the plant will be 1350 megawatts (MW). With this set up, a ‘half-net’ efficiency of more than 52.2 percent is expected [‘half-net’ = gross efficiency with generator power reduced by boiler feed water pump power consumption]. The first, elevated turbine train consists of two high-pressure modules having different pressure stages and one generator and it is located close to the main headers of the boiler at a height of appr. 83 meters. This unique turbine arrangement allows the expensive high-temperature pipes to be shortened, leading to substantially reduced pipe pressure losses and costs. The second turbine train will be installed on a conventional turbine deck at a height of appr. 17 meters and consists of two intermediate pressure and three low pressure turbine modules as well as a second generator. In this paper, the advanced steam turbine technology for this power plant concept is presented and discussed in detail.\u0000 To achieve the next level of efficiency with an SPP today, the application of the 700°C material class is not possible to due to the slow progress of the associated technology development. It is more expedient to exploit the limits of the 600°C material class to the highest possible extent in USC conditions i.e. to the pressures and temperatures mentioned above. Design concept studies have shown that 52.2% ‘half-net’ efficiency cannot be achieved with a single reheat layout, so a double reheat (DRH) layout has been chosen. In addition, 1350 MW cannot be achieved with one turbine train (tandem compound), but only with two turbine trains (cross compound). In order to achieve the highest reliability possible, proven turbine design topologies and features have been used. The major change to the Siemens barrel type VHP turbine was a material change from 10% Chromium steels to FB2 and CB2. The HP turbine received increased wall thicknesses as well as a similar material change compared to a standard USC design. In order to control the oxidation at these elevated temperatures, oxidation protection measures have been applied where required. The startup procedure has been tailored specifically to the needs of a double reheat cross compound config","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115975318","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-Disciplinary Design Optimization of a Horizontal Micro Kaplan Hydro Turbine","authors":"R. Amano, Ahmad I. Abbas, M. Qandil, M. Al-Haddad","doi":"10.1115/gt2019-90509","DOIUrl":"https://doi.org/10.1115/gt2019-90509","url":null,"abstract":"\u0000 This study investigates a performance-based design optimization for a Kaplan hydro turbine at a maximum water head of 2.6 m (8.5 ft), micro-sized horizontal Kaplan turbine with 7.6 cm (3.0 in) diameter that is featured fixed blades to attain the optimum performance for such type and size of hydro turbines. Optimization process includes solving design problems and enhance design development by applying a multi-disciplinary design optimization (MDO) technique. Varying the geometrical parameters of the turbine, i.e., dimensions, number of blades, blade wrap angles, and different rotational speeds (500–3000 RPM) are the relevant proposed disciplines of this study.\u0000 An in-house code is used for optimizing the geometrical parameters of the turbine. A numerical solution that utilizes computational fluid dynamics (CFD) for a 3D, turbulent, transient unsteady and swirl flow is developed using STAR-CCM+ software in conjunction with an experimental setup of a lab-sized closed-loop water system for validation. The performance of the turbine is predicted by evaluating the power output (in watts), mesh independency analysis is also presented for CFD results validation.\u0000 Two multi-simulation matrices were solved by using the high-performance computing (HPC) cluster of the University of Wisconsin-Milwaukee. First matrix includes different number of the blades (3, 4, 5, 6, and 7 blades) over six different rotational speeds (500, 1000, 1500, 2000, 2500, and 3000), while the second matrix includes 121 possible combinations of blade wrap angles starting at 60°-60° (hub-shroud) angle to 110°-110° angle with 5° increment alternated at both sides, the hub and the shroud.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127256879","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":"Improving Accuracy and Comparability of Turbocharger Performance Measurements","authors":"M. Schinnerl, M. Bogner, J. Ehrhard","doi":"10.1115/gt2019-90250","DOIUrl":"https://doi.org/10.1115/gt2019-90250","url":null,"abstract":"\u0000 The reduction of fuel consumption and emissions is the most dominant challenge in powertrain development. Therefore, engine and turbocharger have to be matched with high accuracy to achieve optimum powertrain efficiencies.\u0000 With respect to relevant engine operating points, compressor maps can be measured in full operating range on a standard hot gas test bench. Even though there is no need for extrapolation of the operating range, they have to be corrected for the impact of heat transfer to represent the adiabatic performance of the compressor stage.\u0000 The common approach to evaluate the turbine efficiency is to apply the energy balance of the entire turbocharger where the turbine power is the sum of the compressor power and the friction losses of the radial and axial journal bearings. The adiabatic compressor power in combination with the calculation of the friction losses by using validated run-up simulations enables the evaluation of the isentropic turbine efficiency and the comparability to CFD simulations of the turbine stage.\u0000 For reasons of comparability to CFD simulations, which can predict a wide operating range of the turbine stage, the limited measureable turbine operating range is enhanced by a so-called compressor closed loop unit (CCLU). This additional test device enables to vary the demand of compressor power for the same operating points as in the standard mapping and therefore to enlarge the measureable turbine operating range. In combination with proper extrapolation methods, the isentropic turbine efficiency can now be compared to CFD simulations.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128303328","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}