Radial Ultra-Micro Wave Rotors (UµWR): Design and Simulation

2006 ◽  
Author(s):  
Florin Iancu ◽  
Janusz Piechna ◽  
Norbert Mu¨ller
Keyword(s):  
Reverse Flow ◽  
Three Dimensional ◽  
Axial Flow ◽  
Wave Rotor ◽  
Compression Process ◽  
Radial Wave ◽  
Wave Rotors ◽  
Commercial Code ◽  
Through Flow ◽  
Computational Fluid Dynamics Cfd

It has been shown that the wave rotor technology has the potential of improving the performance of gas turbine cycles. Moreover the radial wave rotor is an additional innovation for this technology. Unlike the commercialized axial-flow wave rotor (Comprex®), a radial one has the benefit of using centrifugal forces to improve the compression process or flow scavenging. The geometry of the rotor is much simpler and is ideal for microfabrication, which is relying mainly on two-dimensional processes to create three-dimensional features. This paper is presenting several radial ultra-micro wave rotors (UμWR) configurations and numerical analysis of these rotors. In a radial placement, the wave rotor has four possible configurations: two - general configuration, through-flow and reverse-flow, and each of these could have the low pressure air port positioned at inside or outside of the rotor. Results have been obtained using FLUENT, a Computational Fluid Dynamics (CFD) commercial code. The vast information about the unsteady processes occurring during simulation is visualized.

scholarly journals Cold Flow Computations for the Diffuser-Combustor Section of an Industrial Gas Turbine

1996 ◽  
Author(s):  
Dadong Zhou ◽  
Ting Wang ◽  
William R. Ryan
Keyword(s):  
Gas Turbine ◽  
Total Pressure ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Complex Flow ◽  
Pressure Losses ◽  
Structured Grid ◽  
Computational Fluid Dynamics Cfd ◽  
Enhance Efficiency ◽  
Industrial Gas Turbine

In the first part of a multipart project to analyze and optimize the complex three-dimensional diffuser-combustor section of a highly advanced industrial gas turbine under development, a computational fluid dynamics (CFD) analysts has been conducted. The commercial FEA code I-DEAS was used to complete the three-dimensional solid modeling and the structured grid generation. The flow calculation was conducted using the commercial CFD code PHOENICS. The multiblock method was employed to enhance computational capabilities. The mechanisms of the total pressure losses and possible ways to enhance efficiency by reducing the total pressure losses were examined. Mechanisms that contribute to the nonuniform velocity distribution of flow entering the combustor were also identified. The CFD results were informative and provided insight to the complex flow patterns in the reverse flow dump diffuser, however, the results are qualitative and are useful primarily as guidelines for optimization as opposed to firm design configuration selections.

Three-Dimensional Flow Phenomena in a Transonic, High-Through-Flow, Axial-Flow Compressor Stage

1992 ◽  
Author(s):  
William W. Copenhaver ◽  
Chunill Hah ◽  
Steven L. Puterbaugh
Keyword(s):  
Flow Field ◽  
Viscous Flow ◽  
Numerical Technique ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Flow ◽  
Compressor Stage ◽  
Complex Flow ◽  
Pressure Transducers ◽  
Through Flow

A detailed aerodynamic study of a transonic, high-through-flow, single stage compressor is presented. The compressor stage was comprised of a low-aspect-ratio rotor combined alternately with two different stator designs. Both experimental and numerical studies are conducted to understand the details of the complex flow field present in this stage. Aerodynamic measurements using high-frequency, Kulite pressure transducers and conventional probes are compared with results from a three-dimensional viscous flow analysis. A steady multiple blade row approach is used in the numerical technique to examine the detailed flow structure inside the rotor and the stator passages. The comparisons indicate that many flow field features are correctly captured by viscous flow analysis, and therefore unmeasured phenomena can be studied with some level of confidence.

scholarly journals A Loss and Deflection Model for Compressor Blading at High Negative Incidence

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Luis E. Ferrer-Vidal ◽  
Marc Schneider ◽  
Alessandro Allegretti ◽  
Vassilios Pachidis
Keyword(s):  
Performance Prediction ◽  
Axial Flow ◽  
Numerical Approach ◽  
Turning Angle ◽  
Blade Cascade ◽  
Through Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Parameters ◽  
Flow Compressor ◽  
Performance Estimates

AbstractWhile significant advances have come about for turbomachinery off-design performance characterization using computational fluid dynamics (CFD), the need for quick performance estimates at challenging off-design conditions still requires the use of lower-order models, such as mean-line analyses and through-flow tools. These inviscid tools require blade performance correlations formulated in terms of loss and turning angle as a function of blade geometric and aerodynamic parameters. Traditionally, such correlations have relied on the empirical data from blade cascade tests at nominal incidence conditions. This limitation on the applicability of the blade correlations has caused performance modeling of the sub-idle regime to be off-limits to this type of correlation-based approaches. This paper addresses the development of blade loss and deviation models applicable to the sub-idle regime using a parametric numerical approach. 2D CFD results are used to generate a model that is then applied to mean-line and through-flow analyses aimed at predicting the sub-idle map of an axial flow compressor. The model proves to be a valuable tool for quick sub-idle performance estimates and allows existing correlation-based performance prediction methods to be extended into the sub-idle regime.

scholarly journals Three-dimensional through-flow modelling of axial flow compressor rotating stall and surge

2018 ◽  
Vol 78 ◽  
pp. 271-279 ◽  
Author(s):  
Mauro Righi ◽  
Vassilios Pachidis ◽  
László Könözsy ◽  
Lucas Pawsey
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Rotating Stall ◽  
Axial Flow Compressor ◽  
Flow Modelling ◽  
Through Flow ◽  
Flow Compressor

Calculation of Fluid Motion in Axial Flow Turbomachines

1968 ◽  
Author(s):  
D. J. L. Smith ◽  
J. F. Barnes
Keyword(s):  
Experimental Work ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Streamline Curvature ◽  
Through Flow ◽  
Loss Distributions ◽  
The Matrix ◽  
Made In

In the last few years considerable progress has been made in calculating the three-dimensional flows through turbomachines. The two methods which appear to be widely used are what have come to be known as the “Streamline Curvature” and the “Matrix Through Flow” methods. At the National Gas Turbine Establishment, these advanced methods have been applied to existing turbomachines and this paper presents some of the calculated and experimental results for four axial flow machines. By making use of fairly simple loss distributions it has been found that these methods can assist towards the understanding of observed phenomena and, in the case of the axial compressor, they offer some prospect of being able to calculate the onset of surge. Also included is a brief report of work in progress to generate a computer program for the solution of the compressible velocity distribution around the surfaces of turbomachine blades, together with an indication of possible future experimental work.

Exergetic and Energetic Response Surfaces for Small Turbojet Engine

2011 ◽  
Vol 110-116 ◽  
pp. 1054-1058
Author(s):  
Onder Turan ◽  
T. Hikmet Karakoc
Keyword(s):  
Mach Number ◽  
Centrifugal Compressor ◽  
Exergy Analysis ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Axial Flow ◽  
Engine Performance ◽  
Response Surfaces ◽  
Operating Parameters ◽  
Turbojet Engine

Exergy analysis permits meaningful efficiencies to be evaluated for a system or process, and the sources, causes and locations of thermodynamic losses to be determined. This study presents exergetic modeling of a small turbojet engine via exergetic response surfaces. Turbojet engine consists of an inlet, a centrifugal compressor, reverse flow combustion chamber, axial-flow turbine and exhaust nozzle. The flight Mach number and altitude are examined on the exergetic efficiencies of total engine performance. The results of analysis are given as three dimensional exergetic response surface plots related to these operating parameters.

Numerical Analysis of the Wave Topping Unit for Small Turbojet

2010 ◽  
Author(s):  
Janusz Piechna ◽  
Rafael Cerpa ◽  
Staniszewski Marcin ◽  
Pezhman Akbari ◽  
Norbert Mu¨ller
Keyword(s):  
Numerical Analysis ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Wave Rotor ◽  
High Rotational Speed ◽  
Machine Performance ◽  
Flow Features ◽  
The Common ◽  
Analysis Models

The paper is focused on the numerical analysis of a wave topping unit used in a small turbojet engine. The analysis focuses on a four-port reverse flow (RF) wave rotor. The special feature of the considered wave rotor is its very high rotational speed. The wave rotor is connected directly with the common shaft between compressor and turbine, thus, the effects of Coriolis accelerations become important. In this study, first a one-dimensional model is used to estimate geometry of the wave rotor and port timings. Then, multi-dimensional analysis models are employed to predict the different flow characteristics inside the wave rotor channels. Three-dimensional flow features that reduce machine performance and influence rotor blade and duct wall thermal loads are identified.

Axial Flow Compressor Design Optimization: Part II — Through-Flow Analysis

1989 ◽  
Author(s):  
Aristide Massardo ◽  
Antonio Satta ◽  
Martino Marini
Keyword(s):  
Design Optimization ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Axial Flow ◽  
Axial Flow Compressor ◽  
Through Flow ◽  
Compressor Design ◽  
Type Calculation ◽  
A New Technique ◽  
Flow Compressor

A new technique is presented for the design optimization of an axial-flow compressor stage. The procedure allows for optimization of the complete radial distribution of the geometry since the variables, chosen to represent the three dimensional geometry of the stage, are coefficients of suitable polynomials. Evaluation of the objective function is obtained with a through-flow type calculation, which has acceptable speed and stability qualities. Some examples are given of the possibility to use the procedure both for redesign and, together with what was presented in Part I, for the complete design of axial-flow compressor stages.

Comparisons on Flow and Temperature Fields for Water-Collecting Box of Diesel Exhaust System

2011 ◽  
Vol 199-200 ◽  
pp. 1532-1536 ◽  
Author(s):  
Xiao Chuan Wang ◽  
Guo He ◽  
Xing Long Pan ◽  
Xiao Ying Shi
Keyword(s):  
Sea Water ◽  
Reverse Flow ◽  
Temperature Drop ◽  
Three Dimensional ◽  
Exhaust System ◽  
Temperature Fields ◽  
Exhaust Gas ◽  
Three Dimensional Model ◽  
Computational Fluid Dynamics Cfd ◽  
Storage Cells

The storage cells of conventional submarines are usually charged up by in the snorkeling state, when the diesel engines that charge the storage cells work underwater. The reverse flow of sea water into the diesel engine from the exhaust pipelines can be avoided effectively by using a water-collecting box (WCB), which has other functions as well. In this paper, a three-dimensional model of WCB was established and based on which the flow and temperature fields were studied by computational fluid dynamics (CFD) computations. From the comparison of distribution on interior fields for four different structural WCBs, an optimized scheme of enhancing the cooling effect and not raising the exhausting resistance was probed. The results show that the temperature drop of exhaust gas after washing the WCB IV (WCB with truncated tubes) is 40 percent higher than that of the WCB I, and the pressure drop has a low of 3 percent as well. The comprehensive characteristics of WCB IV are foremost between the four WCBs.

scholarly journals A Numerical Analysis of an Innovative Flow Ripple Reduction Method for External Gear Pumps

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 471
Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Adolfo Senatore
Keyword(s):  
Reverse Flow ◽  
Control Volume ◽  
Three Dimensional ◽  
Parameter Method ◽  
Gear Pump ◽  
Noise Emission ◽  
Flow Ripple ◽  
Commercial Code ◽  
Innovative Solution ◽  
Gear Pumps

In this paper, an innovative solution to minimize noise emission, acting on the flow ripple, in a prototype External Gear Pump (EGP) is presented. Firstly, a new tool capable to completely simulate this pump’s typologies, called EgeMATor, is presented; the hydraulic model, adopted for the simulation, is based on a lumped parameter method using a control volume approach. Starting from the pump drawing, thanks to different subroutines developed in different environments interconnected, it is possible to analyze an EGP. Results have been compared with the outputs of a three-dimensional CFD numerical model built up using a commercial code, already used with success by the authors. In the second section, an innovative solution to reduce the flow ripple is implemented. This technology is called Alternative Capacitive Volumes (ACV) and works by controlling and uniformizing the reverse flow, performing a consistent reduction of flow non-uniformity amplitude. In particular, a high reduction of the flow non-uniformity is notable in the frequency domain on the second fundamental frequency. The technology is easy to accommodate in a pump housing, especially for high-pressure components, and it helps with reducing the fluid-borne noise.

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