scholarly journals Performance Research and Structure Optimization of Labyrinth Screw Pump

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 790
Author(s):  
Xin Rong ◽  
Hongwu Zhu ◽  
Biao Hu
Keyword(s):  
Response Surface ◽  
Structural Parameters ◽  
Simulation Method ◽  
High Viscosity ◽  
Gas Content ◽  
Low Flow ◽  
Screw Pump ◽  
Surface Theory ◽  
Optimization Parameters ◽  
Neural Network Prediction

The labyrinth screw pump is a new type of low-flow rotor pump with a simple structure and good sealing performance. It is suitable for the transport of high-viscosity, high-gas-content, and particle-containing media. In this study, a rectangular labyrinth screw pump was used as the research object. The effect of the medium viscosity on the performance of the labyrinth pump was studied through numerical simulations, and the correctness of the simulation method was verified using existing test data. The efficiency and head of the labyrinth screw pump were selected as the optimization objectives, and the pump structural parameters were selected as the optimization parameters. A structural optimization model of the labyrinth screw pump based on response surface theory was established. The structural parameters of the labyrinth pump were reasonably simplified through size correlations, and then parameter sensitivity analysis was performed to determine the important structural parameters that needed to be optimized. The OSFD (optimized space-filling design) was used to combine the optimized parameters and generate the sample space. The response surface theory was combined with a neural network prediction model and a multi-objective genetic algorithm to perform optimization calculations. The results showed that there was an interactive influence between the structural parameters of the stator and rotor of the labyrinth screw pump. Compared with the original model, the optimized model pump had an efficiency increase of 13.55% and a lift increase of 19.53% when conveying a medium with a viscosity of 133 cp.

Research on CFD Simulation of the Cement Slurry Mixer

2012 ◽  
Vol 621 ◽  
pp. 196-199
Author(s):  
Shui Ping LI ◽  
Ya Li Yuan ◽  
Lu Gang Shi
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Cfd Simulation ◽  
Structural Parameters ◽  
Internal Flow ◽  
Simulation Method ◽  
Cement Slurry ◽  
Fluid Machinery ◽  
Computational Fluid Dynamics Cfd ◽  
Machinery Design

Numerical simulation method of the internal flow field of fluid machinery has become an important technology in the study of fluid machinery design. In order to obtain a high-performance cement slurry mixer, computational fluid dynamics (CFD) techniques are used to simulate the flow field in the mixer, and the simulation results are studied. According to the analysis results, the structural parameters of the mixer are modified. The results show the mixer under the revised parameters meet the design requirements well. So CFD analysis method can shorten design period and provide valuable theoretical guidance for the design of fluid machinery.

scholarly journals Research of Pressure Fluctuation with Experiment and Numerical Simulation for Dredging Pump

2021 ◽  
Vol 2097 (1) ◽  
pp. 012028
Author(s):  
Mingming Liu ◽  
Haifei Zhuang ◽  
Lei Cao
Keyword(s):  
Numerical Simulation ◽  
Pressure Fluctuation ◽  
Flow Instability ◽  
Simulation Method ◽  
Design Flow ◽  
Low Flow ◽  
Pressure Amplitude ◽  
Main Frequency ◽  
Simulation And Experiment ◽  
Fluctuation Amplitude

Abstract In order to reveal the dredge pump flow instability characteristics, the cavitation and pressure fluctuation in experimental study are carried out, the pressure fluctuation frequency domain and time domain characteristics of three different position inside the volute are analyzed. The results showed that, before cavitation, the main frequency at different positions at different flow rates is 1 times the main frequency of the blade. The fluctuation amplitude near the volute tongue and diffusion section is slightly larger than that at other positions. Before cavitation, the fluctuation amplitude at the same position off design flow is slightly higher than that near the design flow. Cavitation has little influence on the main frequency of the pressure fluctuation. After cavitation, the pressure fluctuation amplitude in the low flow point and the position of the volute tongue under each condition has little change, but cavitation aggravates the pressure fluctuation in the other conditions. Besides, the comparison between simulation and experiment results shows the dredge pump performance curve is in good agreement with the simulation curve, and the simulation results of pressure amplitude at different positions are basically consistent with the experiment results, which verifies the reliability of the numerical simulation method.

scholarly journals Forecasting Low Stream Flow Rate Using Monte—Carlo Simulation of Perigiali Stream, Kavala City, NE Greece

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 580 ◽  
Author(s):  
Thomas Papalaskaris ◽  
Theologos Panagiotidis
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Flow Rate ◽  
Stream Flow ◽  
Simulation Method ◽  
Base Flow ◽  
Low Flow ◽  
Rate Data ◽  
Storm Flow ◽  
Management Plans

A small number of scientific research studies with reference to extremely low flow conditions, have been conducted in Greece, so far. Predicting future low stream flow rate values is an essential and of paramount importance task when compiling watershed and drought management plans, designing water reservoirs and general hydraulic works capacity, calculating hydrological and drought low flow values, separating groundwater base flow and storm flow of storm hydrographs etc. The Monte-Carlo simulation method generates multiple attempts to define the anticipated value of a random (hydrological in this specific case) variable. The present study compiles, correspondingly, artificial low stream flow time series of both the same part of the year (2016) as well as a part of the calendar year (2017), based on the stream flow data observed during the same two different interval periods of the years 2016 and 2017, using a 3-inches U.S.G.S. modified portable Parshall flume, a 3-inches conventional portable Parshall flume, a 3-inches portable Montana (short Parshall) flume and a 90° V-notched triangular shaped sharp crested portable weir plate. The recorded data were plotted against the fitted one and the results were demonstrated through interactive tables providing us the ability to effectively evaluate the simulation procedure performance. Finally, we plot the observed against the calculated low stream flow rate data, compiling a log-log scale chart which provides a better visualization of the discrepancy ratio statistical performance metric and calculate statistics featuring the comparison between the recorded and the forecasted low stream flow rate data.

Development of an advanced turbocharger simulation method for cycle simulation of turbocharged internal combustion engines

2009 ◽  
Vol 223 (5) ◽  
pp. 661-672 ◽  
Author(s):  
W Zhuge ◽  
Y Zhang ◽  
X Zheng ◽  
M Yang ◽  
Y He
Keyword(s):  
Internal Combustion Engines ◽  
Flow Model ◽  
Predictive Accuracy ◽  
Integrated Design ◽  
Simulation Method ◽  
Low Flow ◽  
Model Parameters ◽  
Cycle Simulation ◽  
Cent Error ◽  
Engine Cycle

An advanced turbocharger simulation method for engine cycle simulation was developed on the basis of the compressor two-zone flow model and the turbine mean-line flow model. The method can be used for turbocharger and engine integrated design without turbocharger test maps. The sensitivities of the simulation model parameters on turbocharger simulation were analysed to determine the key modelling parameters. The simulation method was validated against turbocharger test data. Results show that the methods can predict the turbocharger performance with a good accuracy, less than 5 per cent error in general for both the compressor and the turbine. In comparison with the map-based extrapolation methods commonly used in engine cycle simulation tools such as GT-POWER®, the turbocharger simulation method showed significant improvement in predictive accuracy to simulate the turbocharger performance, especially in low-flow and low-operating-speed conditions.

scholarly journals Optimizing Uniaxial Oil Extraction of Bulk Rapeseeds; Spectrophotometric and Chemical Analyses of the Extracted Oil under Pretreatment Temperatures and Heating Intervals

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1755
Author(s):  
Cimen Demirel ◽  
Abraham Kabutey ◽  
David Herák ◽  
Petr Hrabě ◽  
Čestmír Mizera ◽  
...  
Keyword(s):  
Response Surface ◽  
Acid Value ◽  
Statistical Technique ◽  
Deformation Energy ◽  
Oil Extraction ◽  
Heating Time ◽  
Optimization Parameters ◽  
Response Surface Regression ◽  
Processing Optimization ◽  
Experimental Runs

Optimizing the operating factors in edible oil extraction requires a statistical technique such as a response surface methodology for evaluating their effects on the responses. The examined input factors in this study were the diameter of pressing vessel, VD (60, 80, and 100 mm), temperature, TPR (40, 60, and 80 °C), and heating time, HTM (30, 60 and 90 min). The combination of these factors generated 17 experimental runs where the mass of oil, oil yield, oil extraction efficiency, and deformation energy were calculated. Based on the response surface regression analysis, the combination of the optimized factors was VD: 100 (+1) mm; TPR: 80 °C (+1) and HTM: 60 (0) min); VD: 60 (−1) mm; TPR: 80 °C (+1) and HTM: 75 (+0.5) min and VD: 100 (+1) mm; TPR: 80 °C (+1) and HTM: 90 (+1). The absorbance and transmittance values significantly (p < 0.05) correlated with the wavelength and temperature, but they did not correlate significantly (p > 0.05) with heating time. The peroxide value did not correlate significantly with temperature, however, it correlated significantly with heating time. Neither the acid value nor the free fatty acid value correlated with both temperature and heating time. The findings of the present study are part of our continuing research on oilseeds’ processing optimization parameters.

scholarly journals Model of Prediction of Gas Emission based on Gas Content Uncertainty in Coal Mine using Geostatistical Simulation and Monte Carlo Method

2021 ◽  
Author(s):  
Shokofe Rahimi ◽  
Majid Ataee-pour ◽  
Hasan Madani
Keyword(s):  
Monte Carlo ◽  
Coal Seam ◽  
Ventilation System ◽  
Prediction Method ◽  
Simulation Method ◽  
Worker Safety ◽  
Gas Content ◽  
Geostatistical Simulation ◽  
Gas Emission ◽  
Factors Affecting

Abstract It is very difficult to predict the emission of coal gas before the extraction, because it depends on various geological, geographical and operational factors. Gas content is a very important parameter for assessing gas emission in the coal seam during and after the extraction. Large amounts of gas released during the mining cause concern about adequate airflow for the ventilation and worker safety. Hence, the performance of the ventilation system is very important in an underground mine. In this paper, the gas content uncertainty in a coal seam is first investigated using the central data of 64 exploratory boreholes. After identifying the important coal seams in terms of gas emission, the variogram modeling for gas content was performed to define the distribution. Consecutive simulations were run for the random evaluation of gas content. Then, a method was proposed to predict gas emission based on the Monte Carlo random simulation method. In order to improve the reliability and precision of gas emission prediction, various factors affecting the gas emission were investigated and the main factors determining the gas emission were identified based on a sensitivity analysis on the mine data. This method produced relative and average errors of 2% and 0.57%, respectively. The results showed that the proposed model is accurate enough to determine the amount of emitted gas and ventilation. In addition, the predicted value was basically consistent with the actual value and the gas emission prediction method based on the uncertainty theory is reliable.

scholarly journals Prediction and Evaluation of Dynamic Variations of the Thermal Environment in an Air-Conditioned Room Using Collaborative Simulation Method

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5378
Author(s):  
Lin He ◽  
Shunan Zhao ◽  
Guowen Xu ◽  
Xin Wu ◽  
Junlong Xie ◽  
...  
Keyword(s):  
Air Temperature ◽  
Temperature Difference ◽  
Thermal Environment ◽  
Structural Parameters ◽  
Simulation Method ◽  
Outer Diameter ◽  
Control Parameters ◽  
Temperature Uniformity ◽  
Collaborative Simulation ◽  
Dynamic Variations

In this study, a collaborative simulation method is proposed to predict dynamic variations of the thermal environment in an air-conditioned room. The room thermal environment was predicted and analyzed by varying the structural and control parameters of the air conditioner considering the dynamic coupling effect. Connections and regularities were established between the applicable parameters and evaluation indices of the thermal environment. The simulation results demonstrated the interactions among the system structural parameters, control parameters, and the thermal environment. Within a certain parameter range, the evaporator structure exhibited a significant effect on temperature uniformity and vertical air temperature difference, followed by predicted mean vote (PMV) and draught rate (DR). The associated evaluation indices were sensitive to fin spacing, tube spacing, and tube outer diameter, in the same order, which were structural parameters of the evaporator. The effect of the air supply angle on the vertical air temperature difference was evident; however, its influence on the PMV, DR, and temperature uniformity did not indicate consistent variations.

scholarly journals Three-Dimensional Simulation Analysis of the Influence of Slat Structural Parameters on Slat Aerodynamic Noise

2019 ◽  
Vol 37 (6) ◽  
pp. 1129-1137
Author(s):  
Hongjian Wang ◽  
Junyuan Tian ◽  
Wang Luo
Keyword(s):  
Simulation Analysis ◽  
Structural Parameters ◽  
Lift Coefficient ◽  
Three Dimensional ◽  
Close Relation ◽  
Simulation Method ◽  
Aerodynamic Noise ◽  
Vortex Strength ◽  
Noise Radiation ◽  
Slat Noise

Slat aerodynamic noise is one of important components of the frame noise. Adjusting the parameters of the slat structure can suppress the slat noise radiation effectively. Based on the typical multi-element airfoil 30P30N, firstly, by means of adjusting the parameters of slat structure, such as changing relative positions between slat and main airfoil and closing slat gap etc., a new slat profile is obtained; Then, based on the DDES simulation method, the characteristics of vortex distribution is analyzed for the new airfoil structure model, and the directivity and SPL of the far field noise are also investigated; Finally, through comparison analysis of the parameters, the physics of the generation of slat aerodynamic noise is discovered, and effects of slat parameters on the features of slat aerodynamic noise are also obtained. The results of the study show that the vortex strength of the flow around the slat has close relation to the source of slat noise. By means of adjusting slat position parameters and morphing of the slat's trailing edge, the vortex strength of the flow close to the slat cusp is reduced effectively, and further largely reducing the slat noise radiation, which can be achieved with preserving high lift coefficient of the airfoil.

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