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Wyszukujesz frazę "performance prediction" wg kryterium: Temat


Tytuł:
Performance prediction of centrifugal pumps with CFD-tools
Autorzy:
Dick, E.
Vierendeels, J.
Serbruyns, S.
Vande Voorde, J.
Powiązania:
https://bibliotekanauki.pl/articles/1967637.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
centrifugal pumps
CFD analysis
performance prediction
Opis:
The CFD code FLUENT, version 5.4, has been used for the flow analysis of two test pumps of end-suction volute type: one of low specific speed and one of medium specific speed. For both, head as a function of flow rate for constant rotational speed is known from experiments. FLUENT provides three calculation methods for analysis of turbomachinery flows: the multiple reference frame method (MRF), the mixing plane method (MP) and the sliding mesh method (SM). In all three methods, the flow in the rotor is calculated in a rotating reference frame, while the flow in the stator is calculated in an absolute reference frame. In the MRF and MP methods steady flow equations are solved, while in the SM method, unsteady flow equations are solved. The SM method does not introduce physical approximations. The steady methods approximate the unsteady interaction between rotor and stator. The cost of the unsteady method is, however, typically 30 to 50 times higher than the cost of the steady methods. It is found that the MRF and MP methods lead to completely erroneous flow field predictions for flows far away from the best efficiency point. This makes the steady methods useless for general performance prediction.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 579-594
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of influence of internal surface roughness of a fan rotor onto its performance parameters
Autorzy:
Fortuna, S.
Powiązania:
https://bibliotekanauki.pl/articles/175530.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
centrifugal fans
CFD simulation
fan performance prediction
surface roughness of rotor
Opis:
Computional fluid dynamics study and experimental test using the standard methods on flow characteristics of the centrifugal fan, have been presented in this paper. This investigation was performed to determine the influence of internal surface roughness of fan rotor onto its performance parameters. The testing results are presented in form of graphs showing the efficiency, pressure and power in function of flow.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2014, 126; 111-121
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analyzing and forecasting the performance of water drive gas reservoirs
Autorzy:
Lupu, Diana-Andreea
Ştefănescu, Dan-Paul
Foidaş, Ion
Powiązania:
https://bibliotekanauki.pl/articles/298653.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
natural gas reservoirs
recovery factor
water drive mechanism
Fetkovich aquifer model
performance prediction
Opis:
The manner of estimating water drive gas reservoir recovery can vary considerably. Several mathematical models have been developed for estimating water influx in petroleum industry, but the current paper will address the application of Fetkovich aquifer model to predict the gas reservoir performance considering the pressure changes that gradually occur within the aquifer and between the aquifer and reservoir. The applicability of this model has proven to be extremely useful in estimation of initial gas resources, aquifer volume and its parameters, confirming the producing mechanism but also forecasting the production performance of the gas reservoir. The authors will highlight through some case studies, the importance of the water influx analysis and prediction, in particular for natural gas reservoirs, which subsequently allows for adequate planning in optimizing the reserves’ recovery.
Źródło:
AGH Drilling, Oil, Gas; 2019, 36, 1; 143-159
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calm water performance of hard-chine vessels in semi-planing and planing regimes
Autorzy:
Ghadimi, P.
Tavakoli, S.
Dashtimanesh, A.
Powiązania:
https://bibliotekanauki.pl/articles/259591.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
hard-chine vessels
planing and semi-planing regimes
performance prediction
2D+T theory
Opis:
In the current paper, a mathematical model is developed for performance prediction of hard-chin boats which can be used in both semi-planing and planing regimes. The proposed model bases on the 2D+T theory and implements pressure distributions over the length of the hull in order to compute the forces. To determine the forces in the semiplaning range, a function is proposed for the non-dimensional length at which the transom effect appears. Three drag components, which are: frictional drag, induced drag, and spray drag, are considered in the computations performed using an iterative method to satisfy two equilibrium equations. The validity of the proposed method is verified by comparing the predicted trim angle and resistance against the available experimental data. Based on this comparison, it is observed that the proposed method reveals satisfying accuracy in both semi-planing and planing regimes. The method is then used to study variation of hydrodynamic and hydrostatic forces as the hull makes a transition from the semi-planing regime to the planing regime. In addition, different components of the resistance are analyzed.
Źródło:
Polish Maritime Research; 2016, 4; 23-45
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of Mechanical Properties of Woven Fabrics by ANN
Autorzy:
Elkateb, Sherien N.
Powiązania:
https://bibliotekanauki.pl/articles/2171977.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
ANN
artificial neural network
mechanical properties
prediction performance
modelling
woven fabric
Opis:
This study aims to obtain an accurate prediction model of mechanical properties of woven fabric to achieve customer satisfaction. Samples of plain woven fabric were produced from different yarn counts and blend ratios of cotton and polyester of weft yarn at different weft densities. Mechanical properties such as tensile strength, bending stiffness and elongation% in both the warp and weft directions were tested. The prediction model was based on Artificial Neural Networks (ANNs). For each model, thirty-nine samples were used for training and fifteen for testing prediction performance. Findings indicated that the ANN achieved a perfect performance in predicting all properties.
Źródło:
Fibres & Textiles in Eastern Europe; 2022, 4 (151); 54--59
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A universal model to predict roadheaders’ cutting performance
Uniwersalny model do prognozowania postępu prac kombajnów do drążenia tuneli
Autorzy:
Ebrahimabadi, A.
Goshtasbi, K.
Shahriar, K.
Seifabad, M. C.
Powiązania:
https://bibliotekanauki.pl/articles/219388.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
prognozowanie postępu prac
maszyna do drążenia tuneli
drążenie tuneli
wskaźnik kruchości skał
kopalnia węgla w Tabas
performance prediction
roadheader
tunneling
Rock Mass Brittleness Index
Tabas Coal Mine
Opis:
The paper intends to generate a universal model to predict the performance of roadheaders for all kinds of rock formations. In this regard, we first take into account the outcomes of previous attempts to explore the performance of roadheaders in Tabas Coal Mine project (the largest and fully mechanized coal mine in Iran). During those investigations, rock mass brittleness index (RMBI) was defined in order to relate the intact and rock mass characteristics to machine performance. The statistical analysis of data acquired from Tabas field demonstrated that RMBI was highly correlated to instantaneous cutting rate (ICR) of roadheaders (R² = 0.92). With the aim to construct a universal model for predicting the roadheader performance, we have now tried to establish a database consisting measured cutting rate of roadheaders as well as the data gathered from field studies of Tabas Coal Mine project and Besiktas, Kurucesme, Baltalimani, Eyup and Halic tunnels in Turkey. A broad modeling and analysis found a fair relationship, resulting in a new universal predictive model to predict the cutting rate of roadheaders with correlation of 0.73 (R² = 0.73). The application of local and universal models at Tabas Coal Mine showed a remarkable difference between measured and predicted ICR. The mean relative error of 0.359% was found with universal model but it represented lower value (mean relative error of 0.100%) while using local model. It can thus be concluded that instead of generating a universal model, separate localized models for different ground and machine conditions should be developed to improve the accuracy and reliability of the performance prediction models.
W pracy podjęto próbę opracowania uniwersalnego modelu do prognozowania postępu prac kombajnów do drążenia tuneli we wszystkich rodzajach skał. W pierwszym etapie przeprowadzono analizę wyników badań w tym zakresie prowadzonych uprzednio w kopalni węgla Tabas (jest to największa i w pełni zmechanizowana kopalnia węgla w Iranie). W ramach badań zdefiniowano współczynnik kruchości skał (RMBI) w celu określenia zależności pomiędzy właściwościami nienaruszonych warstw skalnych a postępami pracy kombajnów. Analiza statystyczna danych uzyskanych w kopalni Tabas wykazała wysoki poziom korelacji pomiędzy wskaźnikiem RMBI a chwilową prędkością urabiania (ISC) kombajnów do drążenia tuneli (R2 = 0.92). Mając na celu opracowanie uniwersalnego modelu do prognozowania postępu prac kombajnów do drążenia tuneli, autorzy podjęli najpierw próbę stworzenia bazy danych obejmującej zmierzone prędkości urabiania oraz dane uzyskane w trakcie badań polowych w kopalni węgla Tabas, oraz z projektu drążenia tuneli w kopalniach w Besiktas, Kurucesme, Baltalimani, Eyup i Halic w Turcji. W wyniku modelowania i analiz znaleziono w miarę dokładną zależność, prowadzącą do stworzenia uniwersalnego modelu prognozowania prędkości urabiania przy użyciu kombajnów do drążenia tuneli, przy poziomie korelacji 0.73 (R2 = 0.73). Zastosowanie lokalnego i uniwersalnego modelu w kopalni węgla Tabas wykazało znaczne różnice pomiędzy mierzoną a prognozowaną chwilową prędkością urabiania. Średni błąd względny dla modelu uniwersalnego wyniósł 0.359%, w przypadku modelu lokalnego średni błąd względny był na poziomie 0.100%. Stąd też należy wnioskować, że dla poprawy wiarygodności i dokładności prognozowania zamiast tworzenia uniwersalnego modelu, zasadne jest opracowanie odrębnych modeli „lokalnych” uwzględniających konkretne uwarunkowania gruntowe oraz sprzętowe.
Źródło:
Archives of Mining Sciences; 2012, 57, 4; 1015-1026
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metody wyznaczania geometrii i charakterystyk dyszy typu aerospike. Program "PM_Contour"
Methods of contour design and performance prediction of an aerospike nozzle. Program "PM-contour"
Autorzy:
Folusiak, M.
Powiązania:
https://bibliotekanauki.pl/articles/213465.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
dysza typu aerospike
wyznaczanie geometrii dyszy typu aerospike
wyznaczanie chgarakterystyk dyszy typu aerospike
program "PM_contour"
method of contour design of an aerospike nozzle
method of performance prediction of an aerospike nozzle
Opis:
W poniższym artykule przedstawiono i krótko opisano algorytmy służące do wyznaczania geometrii dyszy aerospike. Przedstawiono również i dokładnie opisano jeden z wybranych algorytmów oraz program komputerowy napisany na jego podstawie.
In the paper, existing contour design methods of an aerospike nozzle are presented and briefly described. Methods of contour design and performance prediction implemented in the PM contour program are described in details.
Źródło:
Prace Instytutu Lotnictwa; 2009, 3 (198); 105-115
0509-6669
2300-5408
Pojawia się w:
Prace Instytutu Lotnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Column flotation performance prediction: PCA, ANN and image analysis-based approaches
Autorzy:
Nakhaei, Fardis
Irannajad, Mehdi
Mohammadnejad, Sima
Powiązania:
https://bibliotekanauki.pl/articles/109518.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image analysis
column flotation
froth features
performance
prediction
PCA
ANN
Opis:
The flotation froth surface appearance includes remarkable information, which can be employed as a helpful index for the qualitative evaluation of the process efficiency. Image analysis is a practical technology for the sake of achieving process related information that can be employed in expert controllers in order to amend flotation performance. In this paper, the intelligent modelling of relationship between froth characteristics and the metallurgical performance in a pilot column flotation of iron ore was established. Column flotation tests were carried out at a wide range of operating conditions and the froth features along with the metallurgical performances were specified for each run. The artificial intelligence models suggested for the performance parameters prediction include (1) multi-layer back propagation neural network (BPNN), (2) hybrid BPNN with principal component analysis (PCA). The hybrid network was on the basis of the PCA employment in order to decrease the number of variables to be given as input for BPNN. The relationships between the froth features and metallurgical performance factors were successfully modelled via the use of the two methods. The simulation results revealed that the prediction precision of BPNN model on the basis of all the data was relatively higher than the estimation precision of BPNN based on PCA algorithm. The Hybrid BPNN model that was trained by the pre-processed database of measurements achieved from the PCA can be considered a robust method when training time is of paramount importance in objectives of proces control.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1298-1310
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison between neural networks and multiple regression methods in metallurgical performance modeling of flotation column
Autorzy:
Nakhaei, F.
Irannajad, M.
Powiązania:
https://bibliotekanauki.pl/articles/110822.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
metallurgical performance
separation
neural networks
nonlinear regression
prediction
flotation column
Opis:
Artificial neural networks are relatively new computational tools which their inherent ability to learn and recognize highly non-linear and complex relationships makes them ideally suited in solving a wide range of complex real-world problems. In this research, different techniques (Linear regression, Non-linear regression, Back propagation neural network, Radial Basis Function for the estimation of Cu grade and recovery values in flotation column concentrate are studied. Modeling is performed based on 90 datasets at different operating conditions at Sarcheshmeh pilot plant, a copper concentrator in Iran, which include chemical reagents dosage, froth height, air and wash water flow rates, gas holdup and Cu grade in the rougher feed and flotation column feed, column tail and final concentrate streams. The results of models were also expressed and analyzed by intuitive graphics. The results indicated that a four-layer BP network gave the most accurate metallurgical performance prediction and all of the neural network models outperformed non-linear regression in the estimation process for the same set of data.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 1; 255-266
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microservice-Oriented Workload Prediction Using Deep Learning
Autorzy:
Ştefan, Sebastian
Niculescu, Virginia
Powiązania:
https://bibliotekanauki.pl/articles/2060924.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
microservice
web service
workload prediction
performance modeling
microservice-applications
microservice scaler
Opis:
Background: Service oriented architectures are becoming increasingly popular due to their flexibility and scalability which makes them a good fit for cloud deployments. Aim: This research aims to study how an efficient workload prediction mechanism for a practical proactive scaler, could be provided. Such a prediction mechanism is necessary since in order to fully take advantage of on-demand resources and reduce manual tuning, an auto-scaling, preferable predictive, approach is required, which means increasing or decreasing the number of deployed services according to the incoming workloads. Method: In order to achieve the goal, a workload prediction methodology that takes into account microservice concerns is proposed. Since, this should be based on a performant model for prediction, several deep learning algorithms were chosen to be analysed against the classical approaches from the recent research. Experiments have been conducted in order to identify the most appropriate prediction model. Results: The analysis emphasises very good results obtained using the MLP (MultiLayer Perceptron) model, which are better than those obtained with classical time series approaches, with a reduction of the mean error prediction of 49%, when using as data, two Wikipedia traces for 12 days and with two different time windows: 10 and 15min. Conclusion: The tests and the comparison analysis lead to the conclusion that considering the accuracy, but also the computational overhead and the time duration for prediction, MLP model qualifies as a reliable foundation for the development of proactive microservice scaler applications.
Źródło:
e-Informatica Software Engineering Journal; 2022, 16, 1; art. no. 220107
1897-7979
Pojawia się w:
e-Informatica Software Engineering Journal
Dostawca treści:
Biblioteka Nauki
Artykuł

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