scholarly journals Design of radial impellers: A combined extended analytical and numerical method

2009 ◽  
Vol 223 (4) ◽  
pp. 901-917 ◽  
Author(s):  
P Epple ◽  
B Karic ◽  
Č Ilić ◽  
S Becker ◽  
F Durst ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Method ◽  
High Speed ◽  
High Efficiency ◽  
Design Method ◽  
Design Stage ◽  
Flow Information ◽  
Efficiency Increase ◽  
Commercial Solver ◽  
Speed Characteristic

The use of high-speed radial impellers is very common in blowers for industrial application. It is also very common to manufacture these impellers using circular arc blades. The design process as well is almost always based on former impeller series and experimental data available. In this work, a method is presented to improve the efficiency of radial impellers with a combined analytical and numerical method. This method is based on an extended analytical formulation of the flow in radial impellers, allowing optimizing efficiency in the design stage. It is complemented by the mathematical implementation of a well-known qualitative principle of efficiency optimization according to Carnot. Finally, the torque-speed characteristic of the motor is included in the design stage. The blade shapes are computed using an inverse method. The design is then validated by means of computational fluid dynamics (CFD) computation with a commercial solver. Finally, a prototype was built and measurements were carried out in a test rig. It is also shown that the design method provided very good predictions leading to an efficiency increase of 13 per cent and a maximum flowrate increase of 11 per cent. The design point was also met. It is also shown that the numerical computations and measurements are in good agreement. An analysis of the CFD results is also presented, giving an insight view into the substantial flow information within the old and the new impellers. The method presented is a combined analytical and numerical method suited to design high-efficiency radial impellers considering also the torque-speed characteristic of the motor without the need of a previous impeller series or knowledge of experimental data.

An Extended Analytical and Numerical Design Method With Applications of Radial Fans

2009 ◽  
Author(s):  
Philipp Epple ◽  
Mihai Miclea ◽  
Christian Luschmann ◽  
Caslav Ilic ◽  
Antonio Delgado
Keyword(s):  
Experimental Data ◽  
Numerical Method ◽  
High Speed ◽  
High Efficiency ◽  
Design Method ◽  
Maximum Flow ◽  
Design Stage ◽  
Flow Information ◽  
Efficiency Increase ◽  
Flow Rate Increase

The use of high speed radial impellers is very common in fans for industrial application. It is very common also to manufacture the radial impellers for these fans with circular arc blades. The design process is also almost always based on former impeller series and experimental data available. In this work a method is presented to improve the efficiency of radial impellers with a combined analytical and numerical method. This method is based on a new extended analytical formulation of the flow in radial impellers allowing optimizing efficiency in design stage. The blade shapes are computed with an inverse method. The design is then validated by means of CFD computation. Finally a prototype was built and measurements were carried out in a test rig. It is shown also that the design method delivered very good predictions leading to an efficiency increase of 13% of efficiency and a maximum flow rate increase of 11% absolute. The design point was also met. It is also shown that the numerical computations and measurements are in good agreement. An analysis of the CFD results is also presented, giving insight in the substantial flow information inside the old and the new impeller. The method presented is a combined analytical and numerical method suited to design high efficiency radial impellers without the need of a previous impeller series or knowledge of experimental data.

A Design Method of Radial Fans Considering the Torque-Speed-Characteristic of the Motor

2010 ◽  
Author(s):  
Philipp Epple ◽  
Mihai Miclea ◽  
Klaus Pfannschmidt ◽  
Detlev Grobeis ◽  
Antonio Delgado
Keyword(s):  
High Speed ◽  
Design Method ◽  
Design Procedure ◽  
Design Stage ◽  
Maximum Efficiency ◽  
Cfd Analysis ◽  
Test Rig ◽  
Motor Design ◽  
Line Design ◽  
Speed Characteristic

The use of high speed radial impellers is very common in fans for industrial applications. The most common design case is the one with constant speed. In that case, one assigns the corresponding value to the speed n, hence the speed no longer matters in the further design procedure: it is given and it is constant. However, in many cases the speed is not constant, since it is governed by the torque-speed characteristic of the driving motor. In such a case it is necessary to consider the motor characteristic already at the design stage. In the present work a design method was developed in order to perfectly match the torque-speed characteristic of the radial impeller to the torque-speed characteristic of the driving motor. In such a way it is possible to design an impeller-motor unit with maximum efficiency. The extended impeller mean-line-design formulas presented in Epple [6] were complemented with the equations describing the motor torque-speed-characteristic. Both sets of equations where combined and solved in order to achieve a prescribed operating range at a maximum efficiency. In order to validate the design method, it was applied to an industrial fan which should be improved. That radial fan with spiral casing consisted of the main radial fan and a motor cooling axial fan at the other end of the shaft. This later fan was rotating at a too low speed leading to cooling problems of the motor. Hence, a new fan had to be designed which had to deliver the same hydraulic performance but at higher rotating speeds. This had to be done, however, on the given motor. That could only be done when properly designing an impeller matching its torque-speed characteristic to the torque-speed characteristic of the motor: it was an excellent task to validate the combined impeller-motor design procedure. Under these constrains six designs where performed and validated with a commercial CFD solver. The three best designs according to the CFD results were built as prototypes and measured at a standard test rig. The best design delivered the prescribed head-flow characteristic at an even improved hydraulic efficiency. The higher speed was also properly achieved. The design procedure is described and explained in detail and a detailed CFD analysis is presented, complemented by the experimental data obtained at the test rig. A final comparative analysis of the combined impeller-motor design method, the CFD analysis and the measurements is presented.

Performance Optimization Method for Radial Fans With Combined Vaneless Circular and Volute Diffusers Applied to an Industrial Fan

2008 ◽  
Author(s):  
Philipp Epple ◽  
Mihai Miclea ◽  
Antonio Delgado
Keyword(s):  
Experimental Data ◽  
Numerical Method ◽  
Performance Optimization ◽  
High Speed ◽  
High Efficiency ◽  
Operating Point ◽  
Maximum Efficiency ◽  
Outer Diameter ◽  
Vaneless Diffuser ◽  
Absolute Increase

The use of high speed radial impellers is very common for industrial fans and blowers. The aerodynamic design of these machines can be made through direct or inverse means. The design process is almost always direct, based on the existing impeller series and available experimental data [1]. This paper presents the design results and optimization of high speed radial impellers with combined vaneless radial and volute diffusers used for industrial fans, through a combined analytical–numerical method validated by measurements of prototypes at the test rig. The reduction of the velocity from the outlet of the impeller to the outlet of the vaneless diffuser and hence the velocity at the inlet of the volute has a significant influence on the turbulence intensity and hence on the noise and therefore was a major parameter in determining the outer diameter of the circular vaneless diffuser. The designs where then validated by means of CFD computation, and following the numerical results, prototypes for both the volute and the impeller were built and experimentally investigated. The experimental results confirmed the numerical ones and it was shown that the optimized impeller had an absolute increase in efficiency with 70% at the operating point. One has to mention, that in this design, because of the special medical application, the operating point has to be unusually chosen shifted from the maximum efficiency. The results presented show the potential and advantages of the combined analytical and numerical method suited to perform a coupled design of high efficiency radial impellers and spiral casings. It shows also that new designs and improvement of existing designs are possible without the need of a previous impeller series or knowledge of experimental data.

scholarly journals ИССЛЕДОВАНИЕ ЭКОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ АВТОТРАКТОРНОГО ДИЗЕЛЯ ПРИ РАБОТЕ НА ПРЕДЕЛЬНЫХ СОСТАВАХ ЭТЭ

2019 ◽  
Author(s):  
S.A. Plotnukov ◽  
A.N. Kartashevich ◽  
A.V. Plyago
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Diesel Fuel ◽  
High Speed ◽  
Ecological Indicators ◽  
Experimental Installation ◽  
Optimum Angle ◽  
Rotary Speed ◽  
Definition Of ◽  
Speed Characteristic

Цель исследований экспериментальное определение токсических показателей дизельного двигателя Д-245.5S2 сельскохозяйственного трактора при его работе на этаноло-топливной эмульсии с предельным содержание этанола в смеси. Объект исследования: экспериментальная установка (двигатель Д-245.5S2, электротормозной стенд RAPIDO SAK N670 с балансирной маятниковой машиной). Испытания дизеля проводились в соответствии с ГОСТ 18509-88. Исследования проводились на дизельном топливе и этаноло-топливной эмульсии с содержанием этанола 20 и 50 в смеси. Во время проведения исследований снималась регулировочная характеристика для определения оптимального угла опережения впрыскивания (угол 22 до верхней мертвой точки (ВМТ)). Затем снимались нагрузочные характеристики при частоте вращения коленчатого вала 1800 мин-1 и 1400 мин-1 и скоростная характеристика. Во всех экспериментах производилась фиксация эффективных и экологических показателей. Опираясь на полученные в результате испытаний экспериментальные данные, были установлены зависимости токсических показателей дизеля при его работе на этаноло-топливной эмульсии. Также были выявлены изменения токсичности и дымности отработавших газов при разных составах топлива. Приведены графики нагрузочной характеристики (экологические показатели) работы двигателя на базовом топливе и на этаноло-топливной эмульсии с содержанием 20 и 50 этанола в смеси.The purpose of probes - experimental definition of toxic indicators of diesel engine D-245.5S2 at its work on etanolo-fuel emulsion with limiting the ethanol maintenance in a mixture. Object of probe: experimental installation (engine D-245.5S2, electrobrake stand RAPIDO SAK N670 with balancer by pendular car). Diesel engine tests were spent according to GOST 18509-88. Probes were spent on diesel fuel and etanolo-fuel emulsion with the maintenance of ethanol of 20 and 50 to mixtures. During carrying out of probes the adjusting characteristic, for definition of an optimum angle of an injection advance (a corner 22 to the top dead point (TDP)) acted in film. Then loading characteristics acted in film at rotary speed of a bent shaft of 1800 mines-1 both 1400 mines-1 and the high-speed characteristic. At all experimentals fixing of effective and ecological indicators was made. Leaning against the received experimental data as a result of tests, dependences of toxic indicators of a diesel engine have been established at its work on etanolo-fuel emulsion. Also changes of toxicity and smoke, the fulfilled gases are revealed at different structures of fuel. Schedules of the loading characteristic (ecological indicators) engine works on base fuel and on etanolo-fuel emulsion with the maintenance of 20 and 50 of ethanol in a mixture are resulted.

Performance Prediction of Newton-Rader Propellers

2008 ◽  
Vol 52 (02) ◽  
pp. 124-145
Author(s):  
Yin L. Young ◽  
Zhanke Liu
Keyword(s):  
Numerical Method ◽  
Performance Prediction ◽  
High Speed ◽  
High Efficiency ◽  
Area Ratio ◽  
Structural Performance ◽  
Experimental Measurements ◽  
Cavitation Tunnel ◽  
Blade Area ◽  
Hydroelastic Analysis

In this work, a numerical method is presented for the hydrodynamic and hydroelastic analysis of Newton-Rader (NR) propellers (Newton & Rader 1961). The NR propellers are a well-known series of three-bladed propellers specifically designed, extensively tested, and well documented for high-speed crafts. The tests were conducted at the Vosper Cavitation Tunnel, and the propellers exhibit both face and back cavitation patterns (Newton & Rader 1961). The predicted fully wetted and cavitating performance agreed well with experimental measurements. The results indicate that the NR propellers can achieve high efficiency in both the fully wetted and cavitating regimes if the blades exhibit only back cavitation. However, significant reduction in efficiency was observed in all cases when face cavitation develops. The effects of varying blade area ratio on the hydrodynamic and structural performance are discussed. The importance of hydroelastic effects for both model-scale and full-scale NR propellers in uniform and wake inflow are presented.

Structural Levels Model of Performance Behavior and Collaborative Design of High Speed Milling Cutter

2010 ◽  
Vol 102-104 ◽  
pp. 700-704
Author(s):  
Bin Jiang ◽  
Min Li Zheng ◽  
Chang Xing Qi ◽  
Jia He
Keyword(s):  
Collaborative Design ◽  
High Speed ◽  
High Efficiency ◽  
Design Method ◽  
Small Sample ◽  
Functional Domain ◽  
Milling Cutter ◽  
High Speed Milling ◽  
Structural Levels ◽  
Performance Behavior

High speed milling cutter is a representative cutter for high efficiency cutting, there is the indeterminacy induced by small sample and lacking information in evaluating its performance. By the analysis of cutter characteristics, acquires the data of structure, material and cutting parameter affecting the performance of cutter, and constructs structural levels model of performance behavior in designing cutter. Using the theory of axiomatic design, investigates mapping approach among structural domain, material domain and functional domain, and propounds collaborative design method of multilevel high speed milling cutter. Results of performance analysis and high speed milling experiment show that the model indicates the interaction among structural levels of cutter, and the design method makes the performance of cutter satisfy the requirements of safety, stability and high efficiency cutting.

Design of High-Speed Magnetic Pump Based on the Numerical Simulation

2009 ◽  
Author(s):  
Fanyu Kong ◽  
Zhiqiang Wang ◽  
Cuilan Gao ◽  
Hongli Zhang
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
High Efficiency ◽  
Design Method ◽  
Internal Flow ◽  
Magnetic Coupling ◽  
Magnetic Vector Potential ◽  
Test Results ◽  
Working Situation ◽  
The Magnetic Field

The high-speed magnetic pump has the characteristic of zero leakage, small volume and high efficiency. In order to enhance the performance of high-speed magnetic pump and shorten the design period, the hydraulic components and magnetic coupling are designed on the basis of numerical simulation. The hydraulic components designed initially are applied by the design method of high-speed partial emission pump. The internal flow field of the pump is simulated with the FLUENT CFD software. The distributions of absolute velocity, relative velocity and total pressure of pump are gained. The inlet structure and geometry of the magnetic pump are modified based on the simulation results. The magnetic coupling is designed by using empirical factors. The magnetic field of the magnetic coupling is simulated with 2-D Magnetic Vector Potential (MVP) formula using the ANSYS software. The distributions of magnetic force line at origin, working situation and maximum magnetic rotating angle are obtained. The magnetic torque simulated value approaches the result calculated with the empirical formula. The test results of the improved magnetic pump show that the hydraulic performance and outline dimensions meet requirements. The method of design-simulation-improvement-test is successful.

Estimation of the Comfort Indexes of a Rail Vehicle at Design Stage

2006 ◽  
Author(s):  
Roberto Corradi ◽  
Stefano Melzi ◽  
Francesco Ripamonti ◽  
Mario Romani
Keyword(s):  
Numerical Method ◽  
High Speed ◽  
Design Stage ◽  
High Speed Train ◽  
Rail Vehicle ◽  
Multi Body

This work describes a numerical method allowing to estimate the comfort indexes of a rail vehicle at the very beginning design stage. Thanks to a flexible multi-body code developed by Politecnico di Milano a series of simulations relevant to an AnsaldoBreda high speed train vehicle has been performed. The accelerations on the carbody floor were processed in accordance with the EN 12299 normative and the NMV comfort indexes were calculated. Furthermore a deeper investigation about some aspects that significantly affect the comfort indexes has been carried out.

Circuit-Thermal Collaboration Design Method for Outline Design Stage of Mobile Terminal

2005 ◽  
Author(s):  
Yoshiharu Iwata ◽  
Shintaro Hayashi ◽  
Ryohei Satoh ◽  
Kozo Fujimoto
Keyword(s):  
Boundary Conditions ◽  
High Speed ◽  
High Performance ◽  
Design Method ◽  
Mobile Terminal ◽  
Layout Design ◽  
Thermal Design ◽  
Circuit Board ◽  
Design Stage ◽  
Pareto Solutions

The device layout design on the circuit board has a common method of performing a thermal design after the circuit design that is the main performance. But, there is no remaining budget of thermal design of the high performance mobile terminal. Then, a large feedback loop of the design from thermal detail design to outline design is occurred on high performance mobile terminal design. For this purpose, we build upon the high-speed module-based thermal analysis. But the design time is very long with using the general optimization method, i.e., GA, SA. Then, we need more high-speed design method. For this purpose, we have proposed the modularized high-speed layered thermal design method based on the boundary conditions between modules. In this report, we constructed the high-speed circuit-thermal collaboration design method at the outline design stage. This design method is collaborated at decision of boundary conditions between both circuit-thermal design methods. Furthermore, this design method, which computes the Pareto solutions set by changing the weight of each design performance index, was constructed. Moreover, we performed a layout design of a board with four devices mounted on top of the circuit board as a case study. The collaboration design solution between thermal layout design (total temperature rise of device =>min.) and circuit layout design (total circuit line length => min.) was computed in about 250sec, and the Pareto solutions set were computed in about 5000sec.

scholarly journals Prediction of Propeller Open Water Characteristics for High Speed Boat by CFD Method

2019 ◽  
Vol 9 (1) ◽  
pp. 3701-3706
Keyword(s):  
High Speed ◽  
Open Water ◽  
Design Stage ◽  
Water Characteristics ◽  
Computational Evaluation ◽  
Mesh Density ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Commercial Solver ◽  
Computational Resources

Nowadays with the development of computational resources, calculating the open water characteristics of the propeller using Computational Fluid Dynamics (CFD) has been used widely at the initial design stage because of relatively accurate result, time and cost saving, in comparison with experimental approach. This paper presents the results of computational evaluation of propeller open water characteristics for high speed boat, based on steady RANSE flow model with rotating reference frame approach. The effects of mesh density, mesh generation are analyzed in order to improve obtained numerical results. The well-known Gawn propeller series, that is often used for high speed vessel is used to verify and validate the accuracy of case studies. In this study, the authors use the commercial solver Star CCM+ by SIEMENS

Sign in / Sign up

Export Citation Format

Share Document