scholarly journals Evaluation of Experiments on a Twin Scroll Turbocharger Turbine for Calibration of a Complex 1-D Model

2016 ◽  
Vol 14 (3) ◽  
pp. 11-18 ◽  
Author(s):  
Zdeněk Žák ◽  
Jan Macek ◽  
Petr Hatschbach
Keyword(s):  
Calibration Process ◽  
Radial Turbine ◽  
Partial Admission ◽  
D Model ◽  
Turbine Impeller

Abstract The goal of the contribution is to describe the process of measurement on a twin entry turbocharger turbine, and evaluation of obtained data. A specific feature of the twin entry turbine measurement is the separation of turbine sections. It is necessary to control different conditions in each section to achieve partial admission of the turbine impeller. The results are fundamental for the calibration process of a developed physical 1-D model of a radial turbine with twin scroll.

The Effect of Partial Admission on Multistage Radial Inflow Industrial Steam Turbine

2009 ◽  
Author(s):  
Yijin Li ◽  
Qun Zheng ◽  
Lanxin Sun
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Steam Turbine ◽  
Three Dimensional ◽  
Flow Patterns ◽  
Navier Stokes ◽  
Radial Turbine ◽  
Partial Admission ◽  
Aerodynamic Performances ◽  
Turbine Impeller

Aerodynamic performances of a partial admission multistage radial inflow turbine are investigated with numerical simulation. A three-dimensional unsteady Reynolds-averaged Navier–Stokes solver closed by Baldwin-Lomax model is applied for the computations. The flow field features of the first stages with partial admission are analyzed and discussed. Detailed flow patterns of the partial admission radial turbine impeller are presented here in this paper.

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.

scholarly journals Application of a Radial Turbine 1-D Model

2013 ◽  
Vol 11 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Zdeněk Žák ◽  
Oldřich Vítek ◽  
Jan Macek
Keyword(s):  
Radial Turbine ◽  
D Model

Shrnutí Članek, na několika přikladech, popisuje simulace s využitim 1-D modelu radialni turbiny turbodmychadla. Cilem je popsat současny stav a ukazat potencial 1-D přistupu v oblasti modelovani turbodmychadla. Pro možnost testovani modelů turbiny a kompresoru byly vyvinuty rozmanite simulačni nastroje. Model turbinoveho testovaciho stavu umožňuje provozovat turbinu v široke provozni oblasti. Model zkušebniho stavu turbodmychadel se spalovaci komorou je vhodny pro přiřazeni kompresoru turbině. Članek uzaviraji vysledky fungovani modelu turbiny ve spojeni s modelem virtualniho čtyřtaktniho zažehoveho motoru.

Condensation in Radial Turbines—Part I: Mathematical Modeling

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Sebastian Schuster ◽  
Dieter Brillert ◽  
Friedrich-Karl Benra
Keyword(s):  
Waste Heat ◽  
Saturation Temperature ◽  
Steam Temperature ◽  
Radial Turbine ◽  
Liquid Film Flow ◽  
Quantitative Analyses ◽  
Computational Fluid Dynamics Cfd ◽  
Droplet Liquid ◽  
Radial Turbines ◽  
Turbine Impeller

In this two-part paper, the investigation of condensation in the impeller of radial turbines is discussed. In Paper I, a solution strategy for the investigation of condensation in radial turbines using computational fluid dynamics (CFD) methods is presented. In Paper II, the investigation methodology is applied to a radial turbine type series that is used for waste heat recovery. First, the basic CFD approach for the calculation of the gas-droplet-liquid-film flow is introduced. Thereafter, the equations connecting the subparts are explained and a validation of the models is performed. Finally, in Paper I, condensation phenomena for a selected radial turbine impeller are discussed on a qualitative basis. Paper II continues with a detailed quantitative analyses. The aim of Paper I is to explain the models that are necessary to study condensation in radial turbines and to validate the implementation against available experiments conducted on isolated effects. This study aims to develop a procedure that is applicable for investigation of condensation in radial turbines. Furthermore, the main processes occurring in a radial turbine once the steam temperature is below the saturation temperature are explained and analyzed.

Paper 23: An Experimental Investigation of Non-Steady Flow in a Radial Gas Turbine

1965 ◽  
Vol 180 (10) ◽  
pp. 74-85 ◽  
Author(s):  
R. S. Benson ◽  
K. H. Scrimshaw
Keyword(s):  
Steady Flow ◽  
Mass Flow ◽  
Pulse Generator ◽  
Flow Analysis ◽  
Pulse Frequency ◽  
Exhaust Pipe ◽  
Transient Pressure ◽  
Radial Turbine ◽  
Admission Data ◽  
Partial Admission

Comprehensive steady and non-steady flow tests on a small radial turbine turbo-charger are given. Steady flow tests included both full admission and partial admission over the whole speed and pressure range from zero flow to maximum flow. Non-steady flow tests were carried out over a pulse frequency range from 30 to 70 pulses/s and turbine speeds from 30 000 to 60 000 rev/min with the turbine coupled to the exhaust system of a six-cylinder pulse generator under partial admission conditions. Extensive transient pressure and temperature measurements were taken upstream and downstream (pressure only) of the turbine. The total mass flow and power were also measured. A quasi-steady flow analysis was carried out using the steady flow test data. The tests results showed that for a six-cylinder exhaust pipe configuration, with two exhaust pipes entering separate nozzle segments in the radial turbine, the quasi-steady flow analysis using partial admission data grossly underestimated the mass flow and power output of the turbine. Using full admission data the ratio of measurement mass flow and horsepower to the calculated mass flow and horsepower was nearly always greater than unity. Furthermore, the average turbine efficiency was greater under non-steady flow than under steady flow. The magnitude of the recorded effects was dependent on the pulse frequency and turbine speed.

Investigation on the Degree of Reaction in Twin Scroll Radial Turbines at Different Operating Conditions for Turbocharging Applications

2019 ◽  
Author(s):  
Carlo Cravero ◽  
Davide De Domenico ◽  
Andrea Ottonello
Keyword(s):  
High Performance ◽  
Mean Value ◽  
Operating Conditions ◽  
Axial Thrust ◽  
Degree Of Reaction ◽  
Radial Turbine ◽  
Wide Range ◽  
Partial Admission ◽  
Rotor Losses ◽  
Radial Turbines

Abstract Frequently in turbocharging radial turbine studies, some assumptions have to be done in order to make 1D matching calculations as easy as possible and to develop simulation approaches that can be useful for different purposes, like axial thrust prediction. One of these assumptions concerns the degree of reaction, which is often considered constant and equal to the value 0.5. In standard radial turbines design the velocity triangles are set by the target to keep a mean degree of reaction of 50%, in order to obtain low rotor losses and to minimize the exit swirl to get lower losses in the exhaust diffuser. From the experience gained on radial turbines operating in a wide range of conditions, it is evident that: the degree of reaction presents large variations along a given isospeed (especially at low rotational speed) and the mean value is far from 0.5 (particularly true in high performance applications). In the present work a method for the representation of the degree of reaction for radial turbine is suggested. The approach has been developed onto a twin scroll radial turbine for turbocharging, considering a large dataset of operating conditions (at both equal and partial admission). The discussion and the method suggested are based on a rich database from experimental data and numerical simulations developed by the authors on the 3D configuration of the turbines under investigation.

scholarly journals Radial Turbine Thermo-Mechanical Stress Optimization by Multidisciplinary Discrete Adjoint Method

2020 ◽  
Vol 5 (4) ◽  
pp. 30
Author(s):  
Alberto Racca ◽  
Tom Verstraete ◽  
Lorenzo Casalino
Keyword(s):  
Thermal Stresses ◽  
Efficient Computation ◽  
Radial Turbine ◽  
Discrete Adjoint ◽  
Design Variables ◽  
Back Plate ◽  
Stress Optimization ◽  
Computationally Intensive ◽  
The Cost ◽  
Turbine Impeller

This paper addresses the problem of the design optimization of turbomachinery components under thermo-mechanical constraints, with focus on a radial turbine impeller for turbocharger applications. Typically, turbine components operate at high temperatures and are exposed to important thermal gradients, leading to thermal stresses. Dealing with such structural requirements necessitates the optimization algorithms to operate a coupling between fluid and structural solvers that is computationally intensive. To reduce the cost during the optimization, a novel multiphysics gradient-based approach is developed in this work, integrating a Conjugate Heat Transfer procedure by means of a partitioned coupling technique. The discrete adjoint framework allows for the efficient computation of the gradients of the thermo-mechanical constraint with respect to a large number of design variables. The contribution of the thermal strains to the sensitivities of the cost function extends the multidisciplinary outlook of the optimization and the accuracy of its predictions, with the aim of reducing the empirical safety factors applied to the design process. Finally, a turbine impeller is analyzed in a demanding operative condition and the gradient information results in a perturbation of the grid coordinates, reducing the stresses at the rotor back-plate, as a demonstration of the suitability of the presented method.

Aerodynamic Damping Analysis for Radial Turbine Featuring a Multi-Channel Casing Design

2020 ◽  
Author(s):  
Ahmed Farid Hassan ◽  
Tobias Müller ◽  
Markus Schatz ◽  
Damian M. Vogt
Keyword(s):  
Damping Ratio ◽  
Full Model ◽  
Aerodynamic Damping ◽  
Radial Turbine ◽  
Damping Behavior ◽  
Ansys Cfx ◽  
Partial Admission ◽  
Time Marching ◽  
Opening And Closing ◽  
Spiral Casing

Abstract Radial turbine featuring a Multi-channel Casing (MC) is a new design under investigation for enhancing the turbine controllability. The idea behind this new design is to replace the traditional spiral casing with a MC, which allows controlling the mass flow by means of opening and closing control valves in each channel. The arrangement of the closed and opened channel is called the admission configuration, while the ratio between the counts of the open channels to the total number of channels is called the admission percentage. Among several aspects, when applying different admission configurations, the aerodynamic damping during resonant excitation is considered during the design of the turbine. The present study aims at investigating the effect of different MC admission configurations on the aerodynamic damping as an extension to an aerodynamic forcing study, which already assessed the different forcing patterns associated with these different admission configurations. Due to the asymmetry of the flow in circumferential direction resulting from the different partial admission configurations, the computational model is solved as full 3D time-marching, unsteady flow using ANSYS CFX in a one-way fluid-structure analysis. Two different modeling approaches have been considered in this study to investigate their capability of predicting the damping ratio for different MC admission configurations: a) the conventional isolated rotor approach and b) a full model consisting of the rotor and its casing. The results show that the casing affects the aerodynamic damping behavior, which can only be captured by the full model. Furthermore, the damping ratios for all different admission configurations have been calculated using the full stage model.

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