scholarly journals Prediction of flyrock throw distance in quarries by variable selection procedures and ANFIS modelling technique

2021 ◽  
Author(s):  
Turker Hudaverdi
Keyword(s):  
Predictive Models ◽  
Block Size ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Charge Weight ◽  
Anfis Model ◽  
Multivariate Statistical ◽  
Input Parameters ◽  
Variable Reduction ◽  
Flyrock Prediction

Abstract This study suggests application of variable reduction procedures for flyrock prediction. It was aimed to create robust and non-complex predictive models. Eleven operational blast parameters and rock mass properties were measured in an aggregate quarry. Dominant parameters for flyrock occurrence were determined by multivariate statistical methods. Two parallel ANFIS models were developed for flyrock prediction. The first ANFIS model was constructed based on the results of stepwise regression. Burden-hole diameter ratio, in-situ block size and specific charge are the input parameters of ANFIS 1. The second ANFIS model was created based on the results obtained by factor analysis. Burden-hole diameter ratio, bench height- burden ratio, number of holes and charge weight are used as input parameters for ANFIS 2. The calculated mean absolute percentage errors are lower than eight percent for the ANFIS predictions. The median absolute errors are lower than 5 meters. The study also investigates alternative accuracy measures to evaluate forecasting performance. Standardized errors, normalized errors and Nash–Sutcliffe Efficiency (NSE) were found to be useful for model validation. It is concluded that more than a single model can be created for a specific site. Pre-statistical analysis for variable reduction increases performance of the predictive models. Burden appeared to be a significant parameter for flyrock throw.

Effects of Hole Pitch to Diameter Ratio P/D of Impingement and Film Hole on Laminated Cooling Effectiveness

2017 ◽  
Author(s):  
Weilun Zhou ◽  
Qinghua Deng ◽  
Wei He ◽  
Zhenping Feng
Keyword(s):  
Mass Flux ◽  
Pressure Loss ◽  
Pressure Ratio ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Heat Transfer Analysis ◽  
Internal Cooling ◽  
Cooling Effectiveness ◽  
System Pressure ◽  
The Difference

The laminated cooling, also known as impingement-effusion cooling, is believed to be a promising gas turbine blade cooling technique. In this paper, conjugate heat transfer analysis was employed to investigate the overall cooling effectiveness and total pressure loss of the laminated cooling configuration. The pitch to film hole diameter ratio P/Df of 3, 4, 5, 6, combined with pitch to impingement hole diameter ratio P/Di of 4, 6, 8, 10, are studied at the coolant mass flux G of 0.5, 1.0, 1.5, 2.0 kg/(sm2bar) respectively. The results show that overall cooling effectiveness of laminated cooling configuration increases with the decreasing of P/Df and the increasing of the coolant mass flux in general. However P/Df smaller than 3 may leads to a serious blocking in first few film holes at low coolant mass flux. The large P/Di that makes the Mach number of impingement flow greater than 0.16 may cause unacceptable pressure loss. The increment of overall cooling effectiveness depends on the difference between the deterioration of external cooling and the enhancement of internal cooling. Pressure loss increases exponentially with P/Di and G, and it increases more slowly with P/Df that compared to P/Di and G. The mixing loss takes up the most pressure loss at low coolant mass flux. With the increasing of the whole pressure loss, the proportion of throttling loss and laminated loss becomes larger and finally takes up the most of the whole pressure loss. When the sum of throttling loss and laminated loss is greater than mixing loss, the increment of system pressure ratio is unreasonable that compared to the increment of overall cooling effectiveness.

The Effects of Seawater Immersion on the Bearing Strength of Woven-Glass–Epoxy Prepreg Pin-Loaded Joints

2011 ◽  
Vol 21 (2) ◽  
pp. 153-170 ◽  
Author(s):  
AyŞe Öndürücü
Keyword(s):  
Failure Modes ◽  
Failure Load ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Natural Seawater ◽  
Bearing Strength ◽  
Specimen Width ◽  
Bearing Load ◽  
Mechanically Fastened ◽  
Ultimate Failure

This study considers the bearing strengths and failure modes of woven-glass–epoxy prepreg composite mechanically fastened joints. For the study, the specimens were immersed in natural seawater in the laboratory for over 1 year. The edge distance-to-hole diameter ( E/ D) ratio and the specimen width-to-hole-diameter ratio ( W/ D) were systematically altered during experiments. Failure modes were determined by observing the failure regions on the specimens. Damage progression in pin-loaded specimens prepared from woven-glass–epoxy prepreg was also examined using a scanning electron microscopy for three different percentages of ultimate failure load. According to the experimental investigation results, it was observed that the bearing load values obtained from the specimens immersed in seawater decreased considerably in comparison to unimmersed specimens.

Prediction of Selected Production Goals by Classification Methods

2014 ◽  
Vol 474 ◽  
pp. 115-120 ◽  
Author(s):  
Dominika Jurovatá ◽  
Pavel Važan ◽  
Michal Kebisek ◽  
Pavol Tanuska ◽  
Lukáš Hrčka
Keyword(s):  
Data Mining ◽  
Production Process ◽  
Knowledge Discovery ◽  
Predictive Models ◽  
Classification Methods ◽  
System Behavior ◽  
Planning And Control ◽  
Input Parameters ◽  
Process Behavior ◽  
And Control

The goal of this work was to use the process of knowledge discovery in planning and control of production processes. This work is focused on the prediction of the system behavior from the data of production process. The classification was used as a task of data mining. Some predictive models were created and the predictions of the production process behavior were realized by varying the input parameters using selected methods and techniques of data mining. It can be confirmed that the selected input parameters will lead to the fulfillment of the declared objectives of the process. The process of knowledge discovery has been implemented in the program STATISTICA Data Miner.

Stress concentrations at an oblique hole in a thick flat plate under an arbitrary in-plane biaxial loading

1993 ◽  
Vol 28 (3) ◽  
pp. 223-235 ◽  
Author(s):  
P Stanley ◽  
B J Day
Keyword(s):  
Stress Concentration ◽  
Flat Plate ◽  
Biaxial Loading ◽  
Plate Thickness ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Stress Concentrations ◽  
Photoelastic Investigation ◽  
Concentration Factors ◽  
Stress Concentration Factors

The results of an extensive ‘frozen-stress’ photoelastic investigation of the stresses at isolated oblique holes in thick wide plates subjected to uniform uniaxial tension are used to provide stress concentration factors at holes resulting from any form of biaxial in-plane loading. The work covers plate thickness/hole diameter ratios from 1.3 to 3.0 and hole obliquity angles up to 60 degrees. Over these ranges the effects of changes in the plate thickness/hole diameter ratio are not of major importance but the effects of changes in the angle of obliquity are considerable.

Full Coverage Impingement Heat Transfer: Influence of the Number of Holes

1987 ◽  
Vol 109 (4) ◽  
pp. 557-563 ◽  
Author(s):  
G. E. Andrews ◽  
J. Durance ◽  
C. I. Hussain ◽  
S. N. Ojobor
Keyword(s):  
Heat Transfer ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Unit Surface Area ◽  
Impingement Cooling ◽  
Impingement Heat Transfer ◽  
Large N ◽  
Small Influence ◽  
Unit Surface ◽  
Square Array

The choice of hole diameter in impingement cooling requires the number of holes to be specified and design information is provided for this purpose. The correlations for impingement cooling usually take geometry effects into account by using the pitch-to-diameter ratio (X/D) and this is independent of the number of holes and specified purely by the desired pressure loss at a given flow rate. Impingement heat transfer from a square array of holes was studied for a range of coolant flows G from 0.1 to 1.8 kg/sm2 at a fixed X/D of approximately 10. The number of holes per unit surface area N was varied by a factor of 70 at a constant gap-to-hole diameter ratio Z/D of 4.5 and constant gaps of 3 mm and 10 mm. It was shown that there was a range of N over which there was only a small influence on heat transfer at constant G. However, heat transfer fell at large N due to crossflow effects and at low N due to inadequate surface coverage of the impingement flow.

Total Cooling Effectiveness on Laminated Multilayer for Impingement/Effusion Cooling System

2014 ◽  
Author(s):  
Seon Ho Kim ◽  
Kyeong Hwan Ahn ◽  
Eui Yeop Jung ◽  
Jun Su Park ◽  
Ki-Young Hwang ◽  
...  
Keyword(s):  
Cooling System ◽  
Plate Thickness ◽  
Laminate Plate ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Cooling Effectiveness ◽  
Blowing Ratio ◽  
Single Plate ◽  
Line Array ◽  
Cooling Intensity

The next generation aircraft combustor liner will be operating in more severe conditions. This means that the current cooling system needs significant amounts of cooling air to maintain cooling intensity. The present study investigates experimentally the total cooling effectiveness of an integrated impingement/effusion cooling system (thin perforated laminate plate) and effusion cooling system (single plate) at the same blowing ratio of 0.2 to 1.2. The infrared thermography method was employed to evaluate total cooling effectiveness and to determine the fully developed region of cooling performance. The holes arrays on both plates are 13 × 13 and the centers formed a square pattern (i.e., an in-line array). The perforated laminate plate is constructed of three layers and pins that were installed between the layers. In order to avoid increasing the thickness and volume, the layer thickness-to-hole diameter ratio was 0.29, and the pin height-to-hole diameter ratio, which is equivalent to the gap between the plates, was 0.21. The single plate had the same total plate thickness-to-hole diameter, but was composed of only one layer. As a result, the total cooling effectiveness of the laminate plate is 47% ∼ 141% better than single plate depending on the blowing ratio. Also, a fully developed region appears on the 2nd or 3th row of holes.

Fine Particulate Deposition in an Effusion Plate Geometry

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Bruce Varney ◽  
Brett Barker ◽  
Jeffrey Bons ◽  
Pritheesh Gnanaselvam ◽  
Trent Wolff
Keyword(s):  
Gas Turbine ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Gas Turbine Combustor ◽  
Plate Temperature ◽  
Test Fixture ◽  
Fine Particulate ◽  
Inclination Angles ◽  
Compound Angle ◽  
Plate Geometry

Abstract Fine particulate deposition testing was conducted with an effusion plate geometry representative of a gas turbine combustor liner. Preheated coolant air with airborne particulate was fed into an effusion plate test fixture with the flow parallel to the target plate. The test fixture was in an electric kiln that establishes elevated plate temperature, similar to a gas turbine combustor. Test variables include hole diameter, length/diameter ratio, inclination angle, and compound angle. In addition, coolant and plate temperature were varied independently to determine their influence. All tests were continued until the effusion holes had blocked to produce a 25% reduction in mass flowrate while maintaining constant pressure ratio. The blockage rate was found to be more sensitive to flow temperature than to plate temperature over the range studied. Blockage rate was insensitive to effusion hole diameter from 0.5 to 0.75 mm but increased dramatically for hole diameter below 0.5 mm. Blockage shows a moderate increase with hole length/diameter ratio. The strongest dependency was found with the inclination angle; roughly an order of magnitude increase in blockage rate was documented when increasing from a 30 deg to 150 deg. A compound angle of 45 deg caused a negligible change in blockage rate, while a compound angle of 90 deg increased blockage rate for low inclination angles while decreasing it for high inclination angles. For the flow angle dependency, interpretation is provided by means of computational fluid dynamics (CFD) simulations of the particulate delivery and initial deposition location prediction using the Ohio State University (OSU) deposition model.

Cavitation at Sharp Edge Multi-Hole Baffle Plates

2011 ◽  
Author(s):  
G. J. Holt ◽  
D. Maynes ◽  
J. Blotter
Keyword(s):  
Water Flow ◽  
Plate Thickness ◽  
Diameter Ratio ◽  
Cavitation Number ◽  
Hole Diameter ◽  
Loss Coefficient ◽  
Sharp Edge ◽  
Baffle Plate ◽  
Cavitation Inception ◽  
Critical Cavitation

This paper reports results of an experimental investigation of cavitation caused by water flow through sharp edge multi-hole baffle plates at high speeds and large pressure drops. Such cavitation can be destructive to industrial systems due to the induced pipe wall vibrations that result. Incipient and critical cavitation numbers are design limits that are frequently needed in the design of systems implementing baffle plate type geometries to prevent adverse cavitation effects. The overall baffle plate loss coefficient, point of cavitation inception, and point where critical cavitation occurs are functions of baffle hole size, number of holes, and plate thickness. Sixteen total baffle plates were considered in the study with hole sizes ranging from 0.16 cm to 2.54 cm, total through area ranging between 11% and 60%, plate thickness ranging from 0.32–0.635 cm, and number of holes ranging from 4 to 1800. The plates were mounted in the test section of a 10.2 cm diameter schedule 40 pipe closed water flow loop. The focus of this paper is on how the influencing parameters affect the loss coefficient and the point of cavitation inception. The results show a complex dependency between the baffle plate loss coefficient with total through area ratio and the thickness to baffle hole diameter ratio. In general the loss coefficient decreases with increasing openness and increasing thickness to hole diameter ratio. A model based on the data is proposed to predict the loss coefficient for multi-holed baffle plates. Further, the data show that the cavitation number at the point of cavitation inception increases with increasing openness. However, with regard to the thickness to hole diameter ratio, the cavitation number at inception exhibits a local maximum at a ratio between 0.5 and 1.0. Models to allow prediction of the point of cavitation inception and the point where critical cavitation begins are presented in the paper.

Effect of Burden to Hole Diameter Ratio on Rock Fragmentation by Blasting using LS-DYNA

2019 ◽  
pp. 697-701
Author(s):  
M.I. Shahrin ◽  
R.A. Abdullah ◽  
R. Sa’ari ◽  
M.N.A. Alel ◽  
S. Jeon ◽  
...  
Keyword(s):  
Diameter Ratio ◽  
Hole Diameter ◽  
Rock Fragmentation
Sign in / Sign up

Export Citation Format

Share Document