scholarly journals Performance Prediction of Cross-Flow Fans Using Mean Streamline Analysis

2005 ◽  
Vol 2005 (2) ◽  
pp. 112-116 ◽  
Author(s):  
Jae-Won Kim ◽  
Eun Young Ahn ◽  
Hyoung Woo Oh
Keyword(s):  
Performance Prediction ◽  
Cross Flow ◽  
Prediction Method ◽  
General Purpose ◽  
Operating Conditions ◽  
Performance Predictions ◽  
Performance Curves ◽  
Mean Streamline Analysis ◽  
And Performance ◽  
Cross Flow Fan

This paper presents the mean streamline analysis using the empirical loss correlations for performance prediction of cross-flow fans. Comparison of overall performance predictions with test data of a cross-flow fan system with a simplified vortex wall scroll casing and with the published experimental characteristics for a cross-flow fan has been carried out to demonstrate the accuracy of the proposed method. Predicted performance curves by the present mean streamline analysis agree well with experimental data for two different cross-flow fans over the normal operating conditions. The prediction method presented herein can be used efficiently as a tool for the preliminary design and performance analysis of general-purpose cross-flow fans.

Mean streamline performance analysis of mixed-flow fan impellers covering the low flowrate characteristics

2001 ◽  
Vol 215 (4) ◽  
pp. 513-518 ◽  
Author(s):  
H. W. Oh ◽  
K-Y Kim
Keyword(s):  
Prediction Method ◽  
Internal Flow ◽  
Operating Conditions ◽  
Mixed Flow ◽  
Conceptual Design Phase ◽  
Performance Predictions ◽  
Performance Curves ◽  
Overall Performance ◽  
Mean Streamline Analysis ◽  
Effective Models

The mean streamline analysis using the empirical loss correlations has been developed for performance prediction of industrial mixed-flow fan impellers in the present study. New simple, but effective, models for the additional Euler input work characteristic and a suction recirculation loss due to internal flow reversal under the low flowrate conditions are proposed in this paper. Comparison of overall performance predictions with six sets of test data of mixed-flow fans is accomplished to demonstrate the accuracy of the proposed models. Predicted performance curves by the present set of loss models agree fairly well with experimental data for a variety of mixed-flow fan impellers over the entire operating conditions. The prediction method presented herein can be used efficiently in the conceptual design phase of mixed-flow fan impellers.

An optimum set of loss models for performance prediction of centrifugal compressors

1997 ◽  
Vol 211 (4) ◽  
pp. 331-338 ◽  
Author(s):  
H W Oh ◽  
E S Yoon ◽  
M K Chung
Keyword(s):  
Performance Prediction ◽  
Prediction Method ◽  
General Purpose ◽  
Preliminary Design ◽  
Centrifugal Compressors ◽  
Operational Characteristics ◽  
Performance Curves ◽  
Reliable Performance ◽  
Performance Analyses ◽  
Loss Models

The present study has tested most of the loss models previously published in the open literature and found an optimum set of empirical loss models for a reliable performance prediction of centrifugal compressors. In order to improve the prediction of efficiency curves, this paper recommends a modified parasitic loss model. The performance analyses by using various empirical loss models are also compared with those by the two-zone modelling. Predicted performance curves by the proposed optimum set agree fairly well with experimental data for a variety of centrifugal compressors. The prediction method developed through this study can serve as a tool for preliminary design and assist the understanding of the operational characteristics of general purpose centrifugal compressors.

Performance Prediction Method for Multihull Yachts

1989 ◽  
Author(s):  
Clay Oliver
Keyword(s):  
Performance Prediction ◽  
State Of The Art ◽  
Prediction Method ◽  
Aerodynamic Forces ◽  
Design Studies ◽  
Performance Predictions ◽  
Velocity Prediction ◽  
America’S Cup ◽  
And Performance ◽  
Scale Data

A new performance prediction method for multihull yachts is described. The methods described here, and performance predictions based on these methods were used in the design and modifications of the 1988 America's Cup Defender Stars & Stripes. The method incorporates the type of solution procedures used in state-of-the-art monohull velocity prediction programs. The various models used for hydrodynamic and aerodynamic forces are briefly discussed. The predictive method is validated using full-scale data from C-Class catamarans, a Formula 40 catamaran, a 75-foot “maxicat”, and Stars & Stripes with a soft-sail rig. Several examples of design studies are presented.

scholarly journals Investigating the In-Flow Characteristics of Multi-Operation Conditions of Cross-Flow Fan in Air Conditioning Systems

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 959
Author(s):  
Weijie Zhang ◽  
Jianping Yuan ◽  
Qiaorui Si ◽  
Yanxia Fu
Keyword(s):  
Pressure Distribution ◽  
Flow Rate ◽  
Total Pressure ◽  
Air Conditioning ◽  
Pressure Pulsation ◽  
Flow Characteristics ◽  
Cross Flow ◽  
Operating Conditions ◽  
Aerodynamic Noise ◽  
Cross Flow Fan

Cross-flow fans are widely used in numerous applications such as low-pressure ventilation, household appliances, laser instruments, and air-conditioning equipment. Cross-flow fans have superior characteristics, including simple structure, small size, stable airflow, high dynamic pressure coefficient, and low noise. In the present study, numerical simulation and experimental research were carried out to study the unique secondary flow and eccentric vortex flow characteristics of the internal flow field in multi-operating conditions. To this end the vorticity and the circumferential pressure distribution in the air duct are obtained based on the performed experiments and the correlation between spectral characteristics of multiple operating conditions and the inflow state is established. The obtained results show that when the area of the airflow passage decreases while the area of the eccentric vortex area gradually increases, then the airflow of the cross-flow fan decreases, the outlet expands, and the flow pattern uniformity reduces. It was found that wakes form in the vicinity of the blade and the tail of the volute tongue, which generate pressure pulsation, and aerodynamic noise. The pressure distribution along the inner circumference shows that the total minimum pressure appears in the eccentric vortex near the volute tongue and the volute returns near the zone. Moreover, it was found that the total pressure near the eccentric vortex is significantly smaller than that of the main flow zone. As the flow rate decreases, the pressure pulsation amplitude of the eccentric vortex region significantly increases, while the static and total pressure pulsation amplitudes are gradually increased. Close to the eccentric vortex on the inner side of the blade in the volute tongue area, total pressure is low, total pressure on the outside of the blade is not affected, and pressure difference between the inner and outer sides is large. When the flow rate of the cross-flow fan is 0.4 Qd, there is no obvious peak at the harmonic frequency of the blade passage frequency. This shows that the aerodynamic noise is caused by the main unstable flow.

Analytical Modeling and Performance Study of a Cross Flow Air Dehumidifier Using Liquid Desiccant

2014 ◽  
Vol 875-877 ◽  
pp. 1205-1213 ◽  
Author(s):  
Mohamed M. Bassuoni
Keyword(s):  
Numerical Solutions ◽  
Removal Rate ◽  
Cross Flow ◽  
Operating Conditions ◽  
Maximum Deviation ◽  
Performance Study ◽  
Liquid Desiccant ◽  
Mass Transfer Processes ◽  
And Performance ◽  
Air Conditioning Systems

The dehumidifier is a key component in liquid desiccant air conditioning systems. Various mathematical models of heat and mass transfer processes inside the dehumidifier are introduced and numerically solved in the literature. Analytical solutions have more advantages than numerical solutions in studying the dehumidifier performance parameters. This paper presents the results from an analytical model for the performance of an adiabatic cross flow liquid desiccant air dehumidifier. Calcium chloride is used as desiccant material in this investigation. Both humidity and temperature effectiveness of the dehumidifier are used to predict the performance of the device under various operating conditions. Good accuracy has been found between analytical solution and reliable experimental results with a maximum deviation of +6.63% and -5.65% in the moisture removal rate. The method developed here can be used in the quick prediction of the dehumidifier performance. The exit parameters from the dehumidifier are evaluated under the effects of variables such as air temperature and humidity, desiccant temperature and concentration and air to desiccant flow rates. The results show that hot humid air and desiccant concentration have the greatest impact on the performance of the dehumidifier.

Momentum Exchanges and Energy Transfers in Cross Flow Fans

1987 ◽  
Author(s):  
Joseph Mazur ◽  
Trilochan Singh
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Cross Flow ◽  
Operating Conditions ◽  
Energy Transfers ◽  
Cross Flow Fan

An experimental investigation of the flow in a cross flow fan at three operating conditions is reported. Velocity and pressure maps for the flow field are presented along with a determination of the momentum exchanges and energy transfers between the blading and the flow field regions.

Performance prediction of mixed-flow pumps

1998 ◽  
Vol 212 (2) ◽  
pp. 109-115 ◽  
Author(s):  
E S Yoon ◽  
H W Oh ◽  
M K Chung ◽  
J S Ha
Keyword(s):  
Performance Prediction ◽  
Operating Conditions ◽  
Low Flow ◽  
Mixed Flow ◽  
Loss Model ◽  
Flow Recirculation ◽  
Internal Loss ◽  
The Mean ◽  
Loss Models ◽  
Mean Streamline Analysis

This paper presents the mean streamline analysis using the empirical loss models for performance prediction of mixed-flow pumps with high specific speeds. A new internal loss model to describe the effect of flow separation on the characteristic head-capacity curve with a dip in the low flow range is developed and a modified recirculation loss model for calculation of parasitic loss due to flow recirculation at the impeller exit is suggested in this study. The prediction performance of the proposed method here is tested against four sets of measured total heads and efficiencies of mixed-flow pumps, and it is also compared with that based on two-dimensional cascade theory. Predicted results by the present set of loss models agree very well with experimental data for a variety of mixed-flow pumps over the normal operating conditions.

scholarly journals Performance of Pure Crossflow Heat Exchanger in Sensible Heat Transfer Application

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5489
Author(s):  
Karthik Silaipillayarputhur ◽  
Tawfiq Al-Mughanam
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Research Work ◽  
Cross Flow ◽  
Operating Conditions ◽  
Sensible Heat ◽  
Process Industries ◽  
Flow Heat ◽  
And Performance ◽  
Marginal Improvement

All process industries involve the usage of heat exchanger equipment and understanding its performance during the design phase is very essential. The present research work specifies the performance of a pure cross flow heat exchanger in terms of dimensionless factors such as number of transfer units, capacity rate ratio, and heat exchanger effectiveness. Steady state sensible heat transfer was considered in the analysis. The matrix approach that was established in the earlier work was used in the study. The results were depicted in the form of charts, tables, and performance equations. It was observed that indeterminately increasing the number of transfer units past a threshold limit provided very marginal improvement in the performance of a pure cross flow heat exchanger. Likewise, flow pattern in a heat exchanger is usually assumed either as mixed or unmixed. However, due to various operating conditions, partially mixed conditions do exist. This work considers partially mixed conditions in the tube side of the heat exchanger. The correction factor for heat exchanger effectiveness was developed to accommodate partially mixed flow conditions in the pure cross flow heat exchanger.

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