Meanline Modeling of Radial Inflow Turbine With Twin-Entry Scroll

2012 ◽  
Author(s):  
Carl F. Fredriksson ◽  
Xuwen Qiu ◽  
Nick C. Baines ◽  
Markus Müller ◽  
Nils Brinkert ◽  
...  
Keyword(s):  
Model Prediction ◽  
Good Accuracy ◽  
Cfd Analysis ◽  
Test Results ◽  
Analysis And Design ◽  
Radial Turbine ◽  
Partial Admission ◽  
Radial Inflow Turbine ◽  
Inlet Conditions ◽  
Accuracy Of Prediction

Twin entry turbines are widely used in turbocharging as a means of using the exhaust pulse energy of multi-cylinder engines. For modern engines where high levels of EGR are required, an asymmetric twin-entry turbine has been shown to have considerable advantages. Such turbines require a more developed approach to analysis and design than usual. A meanline model for a radial inflow turbine with twin-entry scroll has been developed. Different total pressures and total temperatures may be specified at each entry. Each volute passage is solved separately from the inlet to the splitter location, where the static pressures of both passages are assumed to be the same. From the volute splitter to the rotor inlet, the two streams mix into one uniform flow following conservation laws of continuity, momentum and energy. Experiments have been conducted on a test stand with a radial turbine with an asymmetric twin-entry scroll, where the inlet conditions can be varied independently for each entry. The test results are compared with the model prediction. A good accuracy of prediction is achieved with a realistic set of modeling coefficients. In the future, insights gained from test data and CFD analysis will be used to develop further the volute mixing model and include explicit partial admission losses in the rotor.

Study on the Steady and Unsteady Aerodynamic Performance of a Radial Inflow Turbine With Small Partial Admission in a Miniature ORC System

2011 ◽  
Author(s):  
Ping Li ◽  
Jianhui Chen ◽  
Di Zhang ◽  
Yonghui Xie
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Rotational Speed ◽  
Rankine Cycle ◽  
Maximum Efficiency ◽  
Unsteady Aerodynamic ◽  
Radial Turbine ◽  
Partial Admission ◽  
Excitation Force ◽  
Radial Inflow Turbine

There is a great deal of residual heat under 350 °C being released into environment, without being used efficiently. Compared to the Rankine cycle with water as its working substance, it is effective to utilize Organic Rankine Cycle (ORC) to recover these waste heats. In the threshold of this paper, a miniature ORC system is proposed, and maximum efficiency of the system is achieved by means of optimal working substance. Moreover, numerical simulation of the partial admission (ε = 0.267) high rotational speed radial inflow turbine, which is the key unit in the system, is fulfilled. At the operating rotational speed of 60000 rpm and the proposed thermodynamic parameters, steady and unsteady flow field in the turbine are investigated with R11 as working fluid. The detailed parameters, such as axial force of rotor, power generated and thermal efficiency of the radial turbine, are analyzed. In addition, the unsteady flow pressure is integrated around the rotor blade profile to provide the unsteady aerodynamic blade force. And subsequently frequencies of unsteady disturbances and excitation force factors are obtained by spectrum analysis, which are of key importance for blade response analysis. The generation, development and dissipation process of the secondary flows, passage vortex and leakage vortex are observed in the flow channel. The results reveal that the partial admission greatly influences the parameters distributions in the flow field and the losses of radial turbine mainly occur at the frontier of the passage in the vicinity of blade root. As is discussed in the analysis of excitation force factor, the radial turbine is safe in the operation. The results discussed in this paper are beneficial for the sequent optimization and manufacture of the miniature turbine.

Performance Characterization of a Twin Scroll Volute for Turbocharging Applications

2018 ◽  
Author(s):  
Carlo Cravero ◽  
Mario La Rocca ◽  
Andrea Ottonello
Keyword(s):  
Experimental Data ◽  
Scientific Literature ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Automatic Design ◽  
Cfd Model ◽  
Radial Turbine ◽  
Wide Range ◽  
Partial Admission

The use of twin scroll volutes in radial turbine for turbocharging applications has several advantages over single passage volute related to the engine matching and to the overall compactness. Twin scroll volutes are of increasing interest in power unit development but the open scientific literature on their performance and modelling is still quite limited. In the present work the performance of a twin scroll volute for a turbocharger radial turbine are investigated in some detail in a wide range of operating conditions at both full and partial admission. A CFD model for the volute have been developed and preliminary validated against experimental data available for the radial turbine. Then the numerical model has been used to generate the database of solutions that have been investigated and used to extract the performance. Different parameters and indices are introduced to describe the volute aerodynamic performance in the wide range of operating conditions chosen. The above parameters can be used for volute development or matching with a given rotor or efficiently implemented in automatic design optimization strategies.

Design of Six Freedom Vibration Acquisition System for Military Vehicle

2012 ◽  
Vol 430-432 ◽  
pp. 1866-1870
Author(s):  
Zhi Xiong Zhu ◽  
Shi Shun Zhu ◽  
Guo Jun Wang ◽  
Yan Zhu
Keyword(s):  
Reference System ◽  
Vibration Spectrum ◽  
Object Oriented ◽  
Linear Acceleration ◽  
Test Results ◽  
Collection System ◽  
Analysis And Design ◽  
Design And Implementation ◽  
Military Vehicle ◽  
Collection Data

Design and implementation of six freedom transportation vibration spectrum collection system is presented in this paper. The Attitude and Heading Reference System (AHRS) is used to capture signals including x, y, z, direction linear acceleration, angular rates around Z-axis and pitch, roll degree. The software’s architecture and modules for host computer is designed with object-oriented analysis and design techniques, and the software is implemented with VC++6.0. The test results show that the system was able to collect vehicular vibration information on time and the collection data was replayed on the vibration platform.

scholarly journals Deriving formulations for forecasting the ultimate strength of locally dented ring-stiffened cylinders under combined axial compression and radial pressure loads

2020 ◽  
Vol 23 (3) ◽  
pp. 640-654
Author(s):  
Do Quang Thang
Keyword(s):  
Ultimate Strength ◽  
Residual Strength ◽  
Good Accuracy ◽  
Uncertainty Modeling ◽  
Radial Pressure ◽  
Mean Value ◽  
Reduction Factor ◽  
The Novel ◽  
Test Results ◽  
Parametric Studies

Introduction: This paper focuses on the derived equations to evaluate the ultimate strength of ring-stiffened cylinders with local denting damage under combined loadings. The damage generation scenarios in this research are representing the collision accidents of offshore stiffened cylinders with supply ships. Methods: Numerical analysis of structures are performed using Abaqus software after validation against the experiments from the authors. The responses from seventeen cylinder specimens are analyzed to develop the numerical methods. Results: Good accuracy results were achieved when comparing the test results and the simulation results. Parametric studies are then performed on design examples of ring-stiffened cylinders when considering both intact and damaged conditions for assessing the reduction factor. Then, the novel simple design equations to assess the residual strength of ring-stiffened cylinders after ship collision are derived based on the regression analysis. These equations have good accuracy with mean value Xm (Uncertainty modeling factor) around 1.0 and together with COV (Coefficient of Variation) lower than 5.3%. Conclusion: The accuracy and reliability of the derived equations are validated by comparing it with the existing test data in open access. It is concluded that the proposed equations have high accuracy and reliability, and convenient application for the purpose of checking the residual strength of dented offshore cylinder under ship collisions.

scholarly journals Crude Palm Oil Prediction Based on Backpropagation Neural Network Approach

2019 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Hijratul Aini ◽  
Haviluddin Haviluddin
Keyword(s):  
Neural Network ◽  
Palm Oil ◽  
Good Accuracy ◽  
Activation Function ◽  
Crude Palm Oil ◽  
Backpropagation Neural Network ◽  
Neural Network Approach ◽  
Learning Function ◽  
Hidden Layer ◽  
Accuracy Of Prediction

Crude palm oil (CPO) production at PT. Perkebunan Nusantara (PTPN) XIII from January 2015 to January 2018 have been treated. This paper aims to predict CPO production using intelligent algorithms called Backpropagation Neural Network (BPNN). The accuracy of prediction algorithms have been measured by mean square error (MSE). The experiment showed that the best hidden layer architecture (HLA) is 5-10-11-12-13-1 with learning function (LF) of trainlm, activation function (AF) of logsig and purelin, and learning rate (LR) of 0.5. This architecture has a good accuracy with MSE of 0.0643. The results showed that this model can predict CPO production in 2019.

Loss analysis of the shrouded radial-inflow turbine for compressed air energy storage

2020 ◽  
pp. 095765092094784
Author(s):  
Ziyi Shao ◽  
Wen Li ◽  
Aiting Li ◽  
Xing Wang ◽  
Xuehui Zhang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Entropy Generation ◽  
Velocity Ratio ◽  
Compressed Air ◽  
Compressed Air Energy Storage ◽  
Suction Surface ◽  
Loss Mechanism ◽  
Cross Sectional ◽  
Radial Turbine ◽  
Radial Inflow Turbine

The shrouded radial-inflow turbine is widely employed as a power generation device in the compressed air energy storage (CAES) system. The loss mechanism and off-designed performance of the shrouded radial turbine are lesser known hitherto and should be deeply understood. Loss analyses of a shrouded radial turbine are conducted numerically based on the first and second laws of thermodynamics in the current study. The relationship between losses and the secondary flow has been discussed in detail. A high proportion of loss in the rotor and outblock passage is found under off-designed conditions. The secondary vortex cores and wake are the primary sources of energy dissipation, while the entropy generation mainly appears at the edge of secondary vortices. The suction-surface separation expands as the velocity ratio is decreased, making the high entropy generation scope on the cross-sectional plane wider. Reducing the seal clearance and avoiding the low velocity ratio conditions are quite necessary to reduce losses. It is recommended the outlet passage should be designed longer than the length of rotor axial chord for a uniform outflow.

Pulse Converters—A Method of Improving the Performance of the Turbocharged Diesel Engine

1973 ◽  
Vol 187 (1) ◽  
pp. 635-647 ◽  
Author(s):  
M. S. Janota ◽  
N. Watson
Keyword(s):  
Pulse Generator ◽  
Test Results ◽  
Turbocharged Diesel Engine ◽  
Turbine Efficiency ◽  
Different Types ◽  
Partial Admission ◽  
Characteristics Analysis ◽  
Pulse Converter ◽  
Flow Loss ◽  
Loss Coefficients

Today, most turbocharged diesel engines operate on the pulse system. This is most effective on those engines whose exhaust manifolds can connect groups of three cylinders to a turbine entry without scavenging interference, e.g. three-, six-, nine- and twelve-cylinder engines. However, when only two cylinders can be connected to each turbine entry, e.g. four-, eight- and sixteen-cylinder engines, without interference, the system is usually less efficient. This is because the widely fluctuating, partial admission turbine conditions lower the average turbine efficiency. Recently, the pulse converter has been developed to improve the performance of such engines. A detailed investigation into the operation and application of the pulse converter has been conducted. Test results from three completely different types of engines showed substantial improvements in performance. The dependence of the pulse converter on engine speed and load, the effect of area variations in the pulse converter and the timing of the interfering exhaust pressure waves have been studied. A comparison of theoretically predicted and measured transient pressures (from a model pulse converter fitted to a pulse generator) was made. The theoretical analysis is based on empirical steady-flow loss coefficients and forms a boundary condition for a method of characteristics analysis. Results are compared with those predicted by the simple constant-pressure theory.

Analysis and Design Recommendations for the Collapse of a Concrete Silo

2011 ◽  
Vol 250-253 ◽  
pp. 2877-2880 ◽  
Author(s):  
Guang Lin Yuan ◽  
Lu Dan Tian
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Structure Design ◽  
Test Results ◽  
Reinforcing Bars ◽  
Design Recommendations ◽  
Analysis And Design ◽  
The Future ◽  
Design And Construction

Accidents of the cement manufacturers’ reinforced concrete silo structures frequently occurred currently in China, because of quality problems, causing enormous losses. The collapse status of a cement raw meal silo is investigated. Combined with the test results of the location and spacing of silo wall’s reinforcing bars, concrete strength, cracks and defects, the reasons for collapse of silo wall are analyzed and design recommendations for concrete silo structures are made. This can give reference to reinforced concrete silo structure design and construction in the future.

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