scholarly journals Design of High Efficiency Blowers for Future Aerosol Applications

2009 ◽  
Author(s):  
Raman Chadha ◽  
Gerald L. Morrison ◽  
Andrew R. McFarland
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Static Pressure ◽  
Pressure Rise ◽  
Electrical Energy ◽  
Design Flow ◽  
Preliminary Design ◽  
Aerosol Sampling ◽  
Wall Functions ◽  
Low Efficiency

High efficiency air blowers to meet future portable aerosol sampling applications were designed, fabricated, and their performance evaluated. A preliminary blower design based on specific speed was selected, modeled in CFD, and the flow field simulated. This preliminary blower size was scaled in planar and axial directions, at different rpm values, to set the Best Efficiency Point (BEP) at a flow rate of 100 L/min (1.67×10−3 m3/s @ room conditions) and a pressure rise of 1000 Pa (4″ WC). Characteristic curves for static pressure rise versus air flow rate through the impeller were generated. Experimentally measured motor/blower combination efficiency (ηEXP) for the preliminary design was around 10%. The low value was attributed to the low efficiency of the D.C. motor used (Chadha, 2005). CFD simulations using the κ–ε turbulent model and standard wall function (non-equilibrium wall functions) approach overpredicted the head values. Enhanced wall treatment under-predicted the head rise but provided better agreement with experimental results. The static pressure rise across the final blower is 1021 Pa at the design flow rate of 100 L/min. Efficiency value based on measured static pressure rise value and the electrical energy input to the motor (ηEXP) is 26.5%, a 160% improvement over the preliminary design.

Influence of Blade Sweep on the Energetic Behavior of Axial Flow Turbomachinery Rotors at Design Flow Rate

2004 ◽  
Author(s):  
Ja´nos Vad ◽  
Ali R. A. Kwedikha ◽  
Helmut Jaberg
Keyword(s):  
Aspect Ratio ◽  
Flow Rate ◽  
Axial Flow ◽  
Pressure Rise ◽  
Design Flow ◽  
Tip Clearance ◽  
Total Efficiency ◽  
Low Aspect Ratio ◽  
Axial Velocity Profile ◽  
Bladed Rotor

Experimental and computational studies were carried out in order to survey the energetic aspects of forward and backward sweep in axial flow rotors of low aspect ratio blading for incompressible flow. It has been pointed out that negative sweep tends to increase the lift, the flow rate and the ideal total pressure rise in the vicinity of the endwalls. Just the opposite tendency was experienced for positive sweep. The local losses were found to develop according to combined effects of sweep near the endwalls, endwall and tip clearance losses, and profile drag influenced by re-arrangement of the axial velocity profile. The forward-swept bladed rotor showed reduced total efficiency compared to the unswept and swept-back bladed rotors. This behavior has been explained on the basis of analysis of flow details. It has been found that the swept bladings of low aspect ratio tend to retain the performance of the unswept datum rotor even in absence of sweep correction.

Dynamic Response of a Centrifugal Blower to Periodic Flow Fluctuations

1986 ◽  
Vol 108 (1) ◽  
pp. 77-82 ◽  
Author(s):  
A. N. Abdel-Hamid
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Pressure Rise ◽  
Rotation Frequency ◽  
Periodic Flow ◽  
Average Flow Rate ◽  
Centrifugal Blower ◽  
Inertia Effects ◽  
Average Flow ◽  
Discharge Flow Rate

Experimental investigation of the dynamic response of a centrifugal blower to periodic flow rate modulations was carried out at different blower operating conditions. For modulation frequencies in the range of 0.0085–0.085 of the shaft rotation frequency, the fluctuating pressures at inlet, discharge, and across a flow orifice were simultaneously measured and analyzed in the time and frequency domains. Measurements of the amplitude and phase of the transfer function between the blower static pressure rise and the discharge flow rate fluctuations indicated that the quasi-steady approximation should be limited to frequencies lower than 0.02 of the shaft rotation frequency. For the same average flow rate, the static pressure rise progressively lagged the discharge flow rate fluctuations as the frequency was increased. The trend was similar to that of the inertia effects of a fluctuating flow in a pipe. For the same frequency these inertia effects increased as the average flow rate through the blower was decreased. Applications of the results to on-line measurements of the slope of the characteristic curve and improved dynamic modeling of centrifugal compressors and blowers are discussed.

scholarly journals Effect of Two- and Three-Dimensionally Designed Guide Vanes with Different Camber Length on Static Pressure Recovery of a Wall-Mounted Axial Fan

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1595
Author(s):  
Yong-In Kim ◽  
Yong-Uk Choi ◽  
Cherl-Young Jeong ◽  
Kyoung-Yong Lee ◽  
Young-Seok Choi
Keyword(s):  
Flow Rate ◽  
Guide Vane ◽  
Dynamic Pressure ◽  
Pressure Rise ◽  
Design Flow ◽  
Low Flow ◽  
Axial Fan ◽  
Flow Angle ◽  
Numerical Effort ◽  
Vane Angle

This study was based on a numerical effort to use the motor support (prop) as a guide vane when the motor of a wall-mounted axial fan was located at the fan outlet while maintaining the structural and spatial advantage. The design for the guide vane followed two- and three-dimensional methods. The inlet vane angle, meridional length (total), and meridional length with a vane angle of zero (0) degrees (linear) were considered as design variables. At the design and some low flow rate points, the 2D design offered the most favorable performance when the meridional length with a vane angle of zero (0) degrees (linear) was 30% based on total length, and was the worst for 70%. The 3D design method applied in this study did not outperform the 2D design. In the 2D design concept, averaging the flow angle for the entire span at the design flow rate could ensure a better pressure rise over a more comprehensive flow rate range than weighting the flow angle for a specific span. In addition, the numerical results were validated through an experimental test, with an important discussion of the swirl (dynamic pressure) component. The influence of the inlet motor and turbulence model are presented as a previous confirmation.

scholarly journals Numerical Prediction and Performance Experiment in an Engine Cooling Water Pump with Different Blade Outlet Widths

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Li ◽  
Xiaofan Zhao ◽  
Weiqiang Li ◽  
Weidong Shi ◽  
Leilei Ji ◽  
...  
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Static Pressure ◽  
Cooling Water ◽  
Internal Flow ◽  
Water Pump ◽  
Centrifugal Pumps ◽  
Suction Surface ◽  
Engine Cooling ◽  
Performance Curves

Changing the blade outlet width is an important method to adjust the performance curves of centrifugal pumps. In this study, three impellers with different blade outlet widths in an engine cooling water pump (ECWP) were numerically simulated based on ANSYS-CFX software. Numerical calculation reliability was validated based on the comparison between simulation results and experimental datum. As the blade outlet width increases, from the performance curves, the investigated ECWP head increases gradually; and the best efficiency point (BEP) offsets to larger flow rate; and the high efficiency region (HER) is becoming larger; and the critical cavitation pressure of the investigated ECWP at BEP increases, which indicates that the cavitation performance at BEP became worse. Compared with the internal flow field, we find vortex appears mainly in the blade passage near the tongue and volute outlet, and the region of the low static pressure is located in the blade inlet suction surface, and impeller inlet and outlet are the regions of high turbulence kinetic energy. Meanwhile, at the same flow rate, with the increase of blade outlet width, the areas of vortex and low static pressure become obvious and bigger.

scholarly journals Effect of Flow Rate and Filter Efficiency on Indoor PM2.5 in Ventilation and Filtration Control

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1061 ◽  
Author(s):  
Ji-Hye Kim ◽  
Myoung-Souk Yeo
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Residential Buildings ◽  
Critical Role ◽  
Particle Model ◽  
Flow Rates ◽  
Filter Efficiency ◽  
Wide Range ◽  
Low Efficiency ◽  
Indoor Pm2.5

Ventilation and filtration control play a critical role in determining indoor PM2.5 (particles less than 2.5 μm in aerodynamic diameter) concentrations of outdoor or indoor origin in residential environments. The objective of this study was to investigate the combined effects of flow rates and filter efficiency on indoor PM2.5 concentrations of residential buildings in Seoul, Korea. Using a particle model based on a mass–balance equation, parametric analysis was performed to examine indoor PM2.5 concentrations according to flow rates and filter efficiency under a wide range of outdoor concentrations and indoor generations. Results showed that ventilation control equipped with a medium–efficiency filter was as effective as that with a high-efficiency filter under normal outdoor concentration and high indoor generation rate conditions. It is not recommended to apply a low-efficiency filter because indoor concentration increases rapidly as outdoor PM2.5 increases when ventilation flow rate is high. For filtration control, it is important to increase both flow rate and filter efficiency in order to improve indoor PM2.5 concentration.

The Experimental Study of Matching Between Centrifugal Compressor Impeller and Diffuser

1999 ◽  
Vol 121 (1) ◽  
pp. 113-118 ◽  
Author(s):  
H. Tamaki ◽  
H. Nakao ◽  
M. Saito
Keyword(s):  
Flow Rate ◽  
Centrifugal Compressor ◽  
Static Pressure ◽  
Pressure Ratio ◽  
Design Flow ◽  
Negative Slope ◽  
Compressor Stage ◽  
Rate Analysis ◽  
System Pressure ◽  
Compressor Impeller

The centrifugal compressor for a marine use turbocharger with its design pressure ratio of 3.2 was tested with a vaneless diffuser and various vaned diffusers. Vaned diffusers were chosen to cover impeller operating range as broad as possible. The analysis of the static pressure ratio in the impeller and the diffusing system, consisting of the diffuser and scroll, showed that there were four possible combinations of characteristics of impeller pressure ratio and diffusing system pressure ratio, The flow rate, QP, where the impeller achieved maximum static pressure ratio, was surge flow rate of the centrifugal compressor determined by the critical flow rate. In order to operate the compressor at a rate lower than QP, the diffusing system, whose pressure recovery factor was steep negative slope near QP, was needed. When the diffuser throat area was less than a certain value, the compressor efficiency deteriorated; however, the compressor stage pressure ratio was almost constant. In this study, by reducing the diffuser throat area, the compressor could be operated at a flow rate less than 40 percent of its design flow rate. Analysis of the pressure ratio in the impeller and diffusing systems at design and off-design speeds showed that the irregularities in surge line occurred when the component that controlled the negative slope on the compressor stage pressure ratio changed.

Effects of Blade Inlet Width on Performance of Centrifugal Pump as Turbine With Special Impeller Using in Turbine Mode

2016 ◽  
Author(s):  
Tao Wang ◽  
Xiaobing Liu ◽  
Xide Lai ◽  
Qiuqin Gou
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
High Efficiency ◽  
Cost Effective ◽  
Pressure Head ◽  
Design Flow ◽  
Hydraulic Loss ◽  
Obvious Effect ◽  
Velocity Moment ◽  
Turbine Mode

A reverse running centrifugal pump is one of the attractive choices in micro-hydropower development and industrial pressure energy recovery. One of the main problems in utilizing pump as turbine (PAT) is that the performance of PAT is usually not ideal due to the impeller with the routine backward curved blades which do not match well with turbine running condition. A cost effective suitable way for solving this problem is to redesign impeller with forward curved blades from turbine working condition while the other components do not undergo any modifications. Blade inlet width is one of the main factors in impeller design. Therefore, research on the influence of blade inlet width on PAT performance is useful. In this paper, based on the constant velocity moment theory, the velocity moment at impeller inlet is acquired, firstly. Next, a relationship expression between blade inlet angle and the design flow rate is deduced. To perform research on blade inlet width influencing PAT’s performance with special impeller, three impellers which inlet widths are 13 mm, 16 mm and 19 mm, respectively, are designed by using ANSYS Bladegen software. Numerical simulation and analysis of the three PATs are performed using a verified computational fluid dynamics (CFD) technique. Comparison of three PATs’ performance curves obtained by CFD, we can find that the blade inlet width has obvious effect on the performance of PAT. The flow rate, required pressure head, generated shaft power, and efficiency at best efficiency point (BEP) increase with the increase of blade inlet width. The flow rates of three PATs at BEP are about 90 m3/h, 100 m3/h and 105 m3/h, respectively, when impeller inlet width varies from 13 mm to 16 mm and 19 mm. The BEP of three PATs shifts towards higher discharge and its high efficiency range becomes wider with the increase of blade inlet width. At above 100 m3/h discharge, the PAT efficiency increases in accordance with the increase of blade inlet width. And the hydraulic loss and turbulence kinetic energy loss within impeller decrease with the increase of blade inlet width. In order to improve efficiency, it is helpful to choose a relatively larger blade inlet width in the design of special impeller using in turbine mode of PAT.

High-Efficiency Design Technique of a Single-Channel Submersible Pump Impeller for Waste Treatment

2015 ◽  
Author(s):  
Bo-Min Cho ◽  
Joon-Hyung Kim ◽  
Young-Seok Choi ◽  
Kyoung-Yong Lee ◽  
Hye-Young Oh ◽  
...  
Keyword(s):  
Objective Function ◽  
Flow Rate ◽  
High Efficiency ◽  
Stokes Equations ◽  
Single Channel ◽  
Design Flow ◽  
Hydrodynamic Performance ◽  
Submersible Pump ◽  
Maximum Increase ◽  
Pump Impeller

This study presents the hydrodynamic analysis and optimization for a single-channel submersible pump impeller. The numerical analysis involved the use of the shear stress transport turbulence model to solve three-dimensional Reynolds-averaged Navier-Stokes equations. The optimization process was based on a radial basis neural network model and was conducted by considering two design variables to control the area from the inlet to the outlet of the impeller. The hydrodynamic performance of the pump impeller was optimized by selecting the efficiency as the objective function. The objective function was numerically assessed via Latin hypercube sampling at design points selected in the design space, and the optimization yielded a maximum increase in efficiency of approximately 1% in terms of the design flow rate, as compared to the initial design. The performance curve for the efficiency was also improved in the high flow rate region. Further details of the internal flow fields between the reference and optimum designs are also analyzed and discussed in this work.

Development of a High Efficiency In-Line Tube Fan Using CFD

2015 ◽  
Vol 32 (1) ◽  
Author(s):  
Hung-Cheng Yen ◽  
Wen-Syang Hsu ◽  
Jeng-Min Huang ◽  
Chi-Wen Lu ◽  
Chin-Nan Hsu
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Design Flow ◽  
Design Flow Rate

AbstractAn in-line tube fan with design flow rate 1 m

Measurement of Performance Characteristics of a Piezoelectric Micro Blower

2013 ◽  
Author(s):  
Takashi Fukue ◽  
Koichi Hirose ◽  
Hirotoshi Terao
Keyword(s):  
Flow Rate ◽  
Measurement System ◽  
Performance Characteristic ◽  
Static Pressure ◽  
Characteristic Curve ◽  
Pressure Rise ◽  
Electronic Equipment ◽  
Cooling Performance ◽  
Cooling Air ◽  
The Relationship

This study conducts a measurement system of a performance of a piezoelectric micro blower. Electronic equipments such as laptop computers and cellular phones become smaller and thinner while their functions become more complex. As a result, a lot of components are mounted in an electronic enclosure and flow passages for the cooling air become narrow. This causes significant pressure drop and general cooling fans cannot supply enough cooling air. To improve cooling performance in small electronic equipment, a new air supply system which combines smaller and thinner size with a high pressure performance characteristic is needed. We focused on a novel piezoelectric micro blower. This blower can supply the airflow with high static pressure using the vibration of the piezoelectric element. This may produce a forced convection cooling with low electric power regardless of the size of electronic equipment and packaging density of electrical devices. However, to predict accurate cooling performance of the piezoelectric micro blower in thermal design, we have to obtain a correct supply flow rate of the blower because the cooling performance of forced convection is significantly dependent on the supply flow rate. Generally, an operating point of the blower, which is the operating pressure and the flow rate in electronic equipment, is the point of intersection of performance characteristic curve, which is the relationship between the blower’s pressure rise and the supply flow rate, and flow resistance curve in equipment. Therefore the measurement of the performance characteristic curve is most important. We tried to develop the measurement system of the performance characteristic curve of the piezoelectric micro blower with high accuracy. We succeeded to measure the relationship between the supply flow rate and the static pressure rise of the micro blower. Moreover, in order to clarify whether the micro blower is available for a cooling method of high-density packaging electronic equipment or not, we tried to investigate the effects of the obstruction, which is mounted in front of the blower, on the performance characteristic. Then, we confirmed whether the performance of the blower is changed by the components mounted near the blower or not.

Sign in / Sign up

Export Citation Format

Share Document