scholarly journals Experimental Validation of the Aerodynamic Performance of an Innovative Counter-Rotating Centrifugal Compressor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2582
Author(s):  
Cheikh Brahim ABED ◽  
Sofiane KHELLADI ◽  
Michael DELIGANT ◽  
Abdellatif EL EL MARJANI ◽  
Moisés SOLIS ◽  
...  
Keyword(s):  
Experimental Data ◽  
Centrifugal Compressor ◽  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Design Method ◽  
Pressure Rise ◽  
Design Tool ◽  
Centrifugal Impeller ◽  
Speed Ratio ◽  
And Control

Turbomachinery with double counter-rotating impellers offers more degrees of freedom in the choice of design and control parameters compared to conventional machines. For these innovative machines, the literature review shows that more publications concerning axial type turbomachines are available than centrifugal ones. This work deals with a design and experimental performance analysis, applied to two counter-rotating impellers of a centrifugal compressor “CRCC”. CRCC was designed with a specifically developed tool based on mean-line approach coupled with optimization algorithms and a stream-curvature through-flow method to satisfy the design criteria. This paper presents an experimental validation of the CRCC design tool and its performances against the baseline “SR”, composed of one centrifugal impeller and a volute for which experimental data are available. CRCC numeric simulations are also validated by experimental data. For a fair comparison between CRCC and SR, the same volute is used for both configurations. The CRCC studied here includes a first conventional impeller with an axial inlet and a radial outlet, while the second impeller is parametrically designed and can be considered a rotating bladed diffuser with a radial inlet and outlet. The obtained results show that CRCC can deliver a pressure rise increase of two compared to SR, along with an increase of isentropic efficiency and also validate the design method of this novel layout. The experimental results also show that the speed ratio of CRCC has a positive effect on the surge and shock margin.

Preliminary Study of a Centrifugal Compressor With Counter-Rotating Impellers: Design and Performances Study

2020 ◽  
Author(s):  
Abed Cheikh Brahim ◽  
Khelladi Sofiane ◽  
Deligant Michael ◽  
El Marjani Abdel ◽  
Farid Bakir
Keyword(s):  
Centrifugal Compressor ◽  
Degrees Of Freedom ◽  
Numerical Data ◽  
Centrifugal Impeller ◽  
Through Flow ◽  
Aerodynamic Performances ◽  
Preliminary Study ◽  
And Performance ◽  
And Control ◽  
Selection Of

Abstract Turbomachinery with double counter-rotating impellers offer more degrees of freedom in the choice of design and control parameters compared to conventional machines. For these innovative machines, the literature review shows that more published works are available concerning axial type turbomachines than centrifugal ones. This work deals with a preliminary design and performance analysis applied to two counter-rotating impellers of a centrifugal compressor. We present here the design practice developed based on 0D/1D models, also coupled with optimization and stream-curvature through-flow methods to satisfy the selected design-criteria. An analyze of aerodynamic performances results are made and compared to those available experimental and numerical data of a baseline configuration, composed of one centrifugal-impeller and a volute. The compressor studied here includes a first conventional impeller with an axial inlet and a mixed or centrifugal outlet. The second impeller is designed parametrically and can be considered as a rotating-diffuser with a radial or mixed inlet and outlet. Ultimately, the numerical simulation results of a selection of candidate solutions are discussed.

An Approximate Three-Dimensional Aerodynamic Design Method for Centrifugal Impeller Blades

1990 ◽  
Vol 112 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Zhao Xiaolu ◽  
Qin Lisen
Keyword(s):  
Centrifugal Compressor ◽  
Design Method ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Design Procedure ◽  
Taylor Series Expansion ◽  
Centrifugal Impeller ◽  
Aerodynamic Design ◽  
Impeller Blade ◽  
Blade Geometry

An aerodynamic design method, which is based on the Mean Stream Surface Method (MSSM), has been developed for designing centrifugal compressor impeller blades. As a component of a CAD system for centrifugal compressor, it is convenient to use the presented method for generating impeller blade geometry, taking care of manufacturing as well as aerodynamic aspects. The design procedure starts with an S2m indirect solution. Afterward from the specified S2m surface, by the use of Taylor series expansion, the blade geometry is generated by straight-line elements to meet the manufacturing requirements. Simultaneously, the fluid dynamic quantities across the blade passage can be determined directly. In terms of these results, the designer can revise the distribution of angular momentum along the shroud and hub, which are associated with blade loading, to get satisfactory velocities along the blade surfaces in order to avoid or delay flow separation.

Paper 20: Application of Non-Steady Flow in a Rotating Duct to Pulsating Flow in a Centrifugal Compressor

1967 ◽  
Vol 182 (8) ◽  
pp. 184-196 ◽  
Author(s):  
R. S. Benson ◽  
A. Whitfield
Keyword(s):  
Boundary Condition ◽  
Steady Flow ◽  
Centrifugal Compressor ◽  
Pressure Loss ◽  
Pressure Ratio ◽  
Computer Calculation ◽  
Design Tool ◽  
Centrifugal Impeller ◽  
Vaneless Diffuser ◽  
Flow Equations

This paper deals with a theoretical approach to study the non-steady flow and wave action in a centrifugal impeller and vaneless diffuser, and also to predict the non-steady flow performance of a centrifugal compressor. This was carried out by replacing the compressor unit by a model which consisted of a simplified rotating duct, a vaneless diffuser, and a cone-shaped pipe which replaced the scroll. A theoretical technique using the method of characteristics and the development of the non-steady flow equations to a rotating duct and radial diffuser is given. The development of the theory and the difficulties encountered are described. In particular, the techniques developed for starting a computer calculation are described. In order to maintain homentropic flow in the impeller and diffuser all losses were assumed to occur at the impeller inlet. A pressure loss boundary condition was developed to enable the steady pressure ratio-mass flow characteristics to be computed. When these values agreed with the experimentally determined characteristics, the boundary condition at the rotor inlet was such that the pressure loss terms allowed for the impeller and diffuser losses. The theoretical results obtained are compared with corresponding experimental results, and the possibility of using this theoretical technique as a design tool is discussed.

Effects Due to the Temperature Measurement Section on the Performance Estimation of a Centrifugal Compressor Stage

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Alessandro Bianchini ◽  
Giovanni Ferrara ◽  
Lorenzo Ferrari ◽  
Valeria Ballarini ◽  
Lorenzo Bianchi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Heat Exchange ◽  
Temperature Measurement ◽  
Centrifugal Compressor ◽  
Numerical Models ◽  
Performance Estimation ◽  
Centrifugal Impeller ◽  
Outlet Section ◽  
Impeller Outlet ◽  
Total Temperature

A wide-ranging analysis was performed by GE Oil & Gas and the University of Florence to investigate the effects on the estimation of centrifugal compressor performance induced by a different choice of the total temperature measurement section. With this goal in mind, the study focused on the analysis of a commonly found discrepancy between the measurements at the impeller outlet section and at the stage exit section. Based on the experimental data collected on a centrifugal impeller, three main physical phenomena were analyzed and discussed in further detail. First, the effect of the heat exchange was examined, and its influence on the total temperature variation throughout the machine was extrapolated. Next, the influence of the heat-exchange phenomena affecting the temperature sensors was evaluated by means of numerical models and physical assumptions. Finally, the effects on the temperature measurement of the flow structure at the impeller outlet were investigated. In particular, a corrective model to account for the thermal inertia of the thermocouples normally applied in this section was applied to the experimental data. The corrected temperatures at the investigated measurement sections were then compared, and their influence on the correct stage performance estimation is discussed in this study.

Study of the Flow in Centrifugal Compressor

2009 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
High Pressure ◽  
Centrifugal Compressor ◽  
High Efficiency ◽  
Design Method ◽  
Pressure Ratio ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Low Flow ◽  
High Pressure Ratio ◽  
Surge Margin

An unshrouded centrifugal compressor would give up clearance very large in relation to the span of the blades, because centrifugal compressors produce a sufficiently large pressure rise in fewer stages. This problem is more acute for a low flow high-pressure ratio impeller. The large tip clearance would cause flow separations, and as a result it would drop both the efficiency and surge margin. Thus a design of a high efficiency and wide operation range for a centrifugal compressor is a great challenge. This paper describes a new development of high efficiency and a large surge margin flow coefficient of 0.145 centrifugal compressor. A viscous turbomachinery optimal design method developed by the authors for axial flow machine was further extended and used in this centrifugal compressor design. The new compressor has three main parts: impeller, a low solidity diffuser and volute. The tip clearance is under a special consideration in this design to allow impeller insensitiveness to the clearance. A three-dimensional low solidity diffuser design method is proposed and applied to this design. This design demonstrated to be successful to extend the low solidarity diffusers to high-pressure ratio compressor. The design performance range showed the total to static efficiency of the compressor being about 85% and stability range over 35%. The experimental results showed that the test results are in good agreement with the design.

Modeling of a Dry Dual Clutch Utilizing a Lever-Based Electromechanical Actuator

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Joško Deur ◽  
Milan Milutinović ◽  
Vladimir Ivanović ◽  
H. Eric Tseng
Keyword(s):  
Experimental Data ◽  
Computational Efficiency ◽  
Experimental Validation ◽  
Operating Parameters ◽  
Electromechanical Actuator ◽  
Model Parameterization ◽  
Clutch System ◽  
Wide Range ◽  
Modeling Accuracy ◽  
And Control

The paper proposes a dynamic model of an automotive dry dual clutch system, which comprises submodels of a lever-based electromechanical actuator and a dual clutch assembly. The model is developed by using the bond graph approach, and it can be used for clutch design, analysis, and control tasks. Special attention is devoted to modeling of friction, compliance, and lever geometry effects, as they are the ones that predominantly determine the accuracy of clutch static curve description and computational efficiency of the model. Several custom-designed test rigs are utilized for the purpose of collecting the experimental data needed for model parameterization and validation. Experimental validation demonstrates a good modeling accuracy for a wide range of operating parameters.

Pumping Unit Power-Density Improvement by Application of Counter-Rotating Impellers Design

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Stefano Tosin ◽  
Jens Friedrichs ◽  
Andreas Dreiss
Keyword(s):  
Power Density ◽  
Design Method ◽  
Design Tool ◽  
Single Stage ◽  
Production Costs ◽  
Energy Concentration ◽  
Experimental Investigations ◽  
Speed Ratio ◽  
Numerical Predictions ◽  
House Design

In many industrial areas, downsizing the pumping system is a decisive aim of the designers. The reasons could be multiple means; in a single-stage pump, increasing the power density of the pump means actually reducing the production costs. The main goal of this study was the comparison in terms of power density of a conventionally designed single-stage pump with a novel design concept based on the counter-rotating (CR) principle. In order to simplify the experimental investigations for the present study, the volute geometry was fixed instead of reducing the pump outflow diameters for a fixed design point. The energy concentration was then increased by raising the developed hydraulic power within the same envelope. The design of the impellers was carried out with an in-house design tool, based on inverse design method. Numerical results highlight the advantageousness of the new layout, in terms of power concentration, compared to the conventional impeller. Numerical predictions are also in significant agreement with the experimental investigation results, obtained in a specifically developed CR motors test rig. The experimental optimization of the rotational speed ratio of the CR impellers has shown the possibility to further increase the head in off-design condition and thereby the pump power density.

scholarly journals On Differential Mechanisms for Underactuated, Lightweight, Adaptive Prosthetic Hands

2021 ◽  
Vol 15 ◽  
Author(s):  
Geng Gao ◽  
Mojtaba Shahmohammadi ◽  
Lucas Gerez ◽  
George Kontoudis ◽  
Minas Liarokapis
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Minimal Set ◽  
Prosthetic Devices ◽  
Multiple Degrees Of Freedom ◽  
Prosthetic Hands ◽  
Promising Application ◽  
End Effectors ◽  
Critical Components ◽  
And Control

Over the last decade underactuated, adaptive robot grippers and hands have received an increased interest from the robotics research community. This class of robotic end-effectors can be used in many different fields and scenarios with a very promising application being the development of prosthetic devices. Their suitability for the development of such devices is attributed to the utilization of underactuation that provides increased functionality and dexterity with reduced weight, cost, and control complexity. The most critical components of underactuated, adaptive hands that allow them to perform a broad set of grasp poses are appropriate differential mechanisms that facilitate the actuation of multiple degrees of freedom using a single motor. In this work, we focus on the design, analysis, and experimental validation of a four output geared differential, a series elastic differential, and a whiffletree differential that can incorporate a series of manual and automated locking mechanisms. The locking mechanisms have been developed so as to enhance the control of the differential outputs, allowing for efficient grasp selection with a minimal set of actuators. The differential mechanisms are applied to prosthetic hands, comparing them and describing the benefits and the disadvantages of each.

scholarly journals Performance evaluation of high-lift hydrofoils with a flap used in the design of horizontal-axis hydrokinetic turbines

2021 ◽  
Vol 19 ◽  
pp. 391-395
Author(s):  
A. Rubio-Clemente ◽  
◽  
J. Aguilar ◽  
E. Chica
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Cfd Simulation ◽  
Horizontal Axis ◽  
Hydrodynamic Performance ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Three Dimensional Model ◽  
High Lift ◽  
Hydrokinetic Turbines

The hydrodynamic performance and the flow field of two horizontal-axis hydrokinetic turbines with and without a high-lift hydrofoil with a flap were investigated using computational fluid dynamics (CFD) simulation. For improving the accuracy of the numerical simulation, the user-defined function (UDF) of 6-degrees of freedom (6-DoF) was used in the Ansys Fluent software. Unsteady Reynolds-averaged Navier–Stokes (URANS) equations coupled to the SST 𝑘 − 𝜔 turbulence model were employed during the simulation. A three-dimensional model of both of the turbines with three blades was conducted for obtaining the performance curve of the power coefficient (𝐶𝑃) versus the tip speed ratio (TSR). The maximum power coefficients (𝐶𝑃𝑀𝑎𝑥) of the hydrokinetic turbines with and without a high-lift hydrofoil arrangement were 0.5050 and 0.419, respectively. Experimental data from the literature were used for the validation of the numerical results, specifically for the case when a rotor with traditional blades is utilized. In general, the simulation results were in good agreement with the experimental data.

scholarly journals Numerical Simulation of Flow through a Centrifugal Impeller

2019 ◽  
Vol 8 (11) ◽  
pp. 2997-3003 ◽  
Keyword(s):  
Centrifugal Compressor ◽  
Static Pressure ◽  
Pressure Rise ◽  
Suction Side ◽  
Axial Direction ◽  
Secondary Flows ◽  
Centrifugal Impeller ◽  
Mass Flow Rates ◽  
Flow Through ◽  
Mixing Losses

The paper reports computational results of the flow through an impeller (backward curved) of a centrifugal compressor. 3D steady state investigations are performed at off-design and design mass flow rates. The static pressure as well as stagnation pressure distribution contours and velocity vector reveals the behavior of flow through the impeller at different flow coefficients. The flow pattern observed within the impeller passage is complex and influenced by several factors. Flow through the impeller is distorted due to presence of jet and wake. As flow happens through the impeller, energy is transferred from the impeller’s blades to the fluid. This creates the jet at pressure side region and wake at suction side region of the impeller. This fluid with different energy level gets mixed at the exit of the impeller causing mixing losses as well as secondary flows. These loss leads to a considerable fall in static pressure rise in the compressor and thereby affecting the overall efficiency of the centrifugal compressor. Also, existence of vortices in the flow field as flow turned from axial direction to radial is seen.

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