The Study of the Mathematical Model between Thermal Conductivity and Graphitization Degree of Different Carbon Materials

2011 ◽  
Vol 233-235 ◽  
pp. 3010-3013 ◽  
Author(s):  
Lian Xing Wang ◽  
Yan Wen Zhang ◽  
Ming Lin Jin ◽  
Xiao Long Zhou ◽  
Yang Hu
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Relative Error ◽  
Carbon Materials ◽  
Test Results ◽  
Application Research ◽  
Graphitization Degree ◽  
Factors Influencing ◽  
Different Types ◽  
The Mathematical Model

This article chose three different types of carbon materials as objects, through analyzing the various factors influencing the thermal conductivity; we were to raise the basic mathematical model between the thermal conductivity and graphitization degree. At the same time the correct value in some articles was chosen to establish the corresponding mathematical model of three kinds of carbon materials. After inspection by test results, This model’s relative error was within 7%.The model brought up by this paper has the vital significance to predict the thermal conductivity of the carbon materials and guide the deep application research.

The Estimation of the Thermal Properties of Refractory Materials According to the Temperatures Acceleration Curve at the Blast Furnace Blowing-In

2015 ◽  
Vol 1095 ◽  
pp. 476-482 ◽  
Author(s):  
A.N. Dmitriev ◽  
Maxim O. Zolotykh ◽  
Yury A. Chesnokov ◽  
Oleg Yu. Ivanov ◽  
Galina Yu. Vitkina
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Blast Furnace ◽  
Thermal Properties ◽  
Thermal Conductivity Coefficient ◽  
Refractory Materials ◽  
Different Types ◽  
Definition Of ◽  
The Mathematical Model

In a laying of a hearth it is usually used to ten different types of the flameproof materials. The characteristics of materials declared by the manufacturer can differ from the actual. For creation of the mathematical model [1, 2] temperatures distributions in a laying of the concrete furnace it is necessary to know thermal conductivity of materials of the specific parties used at construction of the furnace. Definition of the thermal conductivity coefficient allows adapt mathematical model for specific conditions of use. The technique of determination of thermal properties of refractory materials on the temperatures acceleration curve at blowing-in of the blast furnace is described.

Constant Speed Motion Simulation and Error Analysis of Planar Non-Circular Curve Parts

2012 ◽  
Vol 220-223 ◽  
pp. 1559-1563
Author(s):  
Rui Wu ◽  
Li Bao ◽  
Yuan Kui Xu
Keyword(s):  
Mathematical Model ◽  
Error Analysis ◽  
Relative Error ◽  
Plane Curve ◽  
Simulation System ◽  
Constant Speed ◽  
Motion Simulation ◽  
Production Practice ◽  
The Mathematical Model ◽  
Circular Curve

The relative direction for a constant speed can be determined according to the planar non-circular curve parts. To establish the mathematical model, a constant speed motion simulation system is designed. The parameters of (vH=5mm/s, δ<3") is commonly used for the simulation system to simulate the movement of drawing the error curve. The results show that by controlling the movement of the plane curve parts in mathematical model can derive the basic constant speed, the relative error of constant speed is less than 3%, it provides a reliable bias when apply to production practice.

An enhanced composting process with bioaugmentation: Mathematical modelling and process optimization

2021 ◽  
pp. 0734242X2110337
Author(s):  
Tea Sokač ◽  
Anita Šalić ◽  
Dajana Kučić Grgić ◽  
Monika Šabić Runjavec ◽  
Marijana Vidaković ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Model Simulation ◽  
Process Conditions ◽  
Air Flow Rate ◽  
Optimal Process ◽  
Composting Process ◽  
Different Types ◽  
Adiabatic Reactor ◽  
The Mathematical Model ◽  
Good Agreement

In this paper, two different types of biowaste composting processes were carried out – composting without and with bioaugmentation. All experiments were performed in an adiabatic reactor for 14 days. Composting enhanced with bioaugmentation was the better choice because the thermophilic phase was achieved earlier, making the composting time shorter. Additionally, a higher conversion of substrate (amount of substrate consumed) was also noticed in the process enhanced by bioaugmentation. A mathematical model was developed and process parameters were estimated in order to optimize the composting process. Based on good agreement between experimental data and the mathematical model simulation results, a three-level-four-factor Box-Behnken experimental design was employed to define the optimal process conditions for further studies. It was found that the air flow rate and the mass fraction of the substrate have the most significant effect on the composting process. An improvement of the composting process was achieved after altering the mentioned variables, resulting in shorter composting time and higher conversion of the substrate.

Low-cost flow-rate estimate in separate layers along gas wells from temperature and pressure profiles

2013 ◽  
Vol 53 (1) ◽  
pp. 285
Author(s):  
Emile Barrett ◽  
Imran Abbasy ◽  
Chii-Rong Wu ◽  
Zhenjiang You ◽  
Pavel Bedrikovetsky
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Flow Rate ◽  
Low Cost ◽  
Pressure Sensors ◽  
Gas Wells ◽  
Production Rates ◽  
Pressure Profiles ◽  
Temperature And Pressure ◽  
The Mathematical Model

Estimation of rate profile along the well is important information for reservoir characterisation since it allows distinction of the production rates from different layers. The temperature and pressure sensors in a well are small and inexpensive; while flow meters are cumbersome and expensive, and affect the flow in the well. The method presented in this peer-reviewed paper shows its significance in predicting the gas rate from temperature and pressure data. A mathematical model for pressure and temperature distributions along a gas well has been developed. Temperature and pressure profiles from nine well intervals in field A (Cooper Basin, Australia) have been matched with the mathematical model to determine the flow rates from different layers in the well. The presented model considers the variables as functions of thermal properties at each location, which is more accurate and robust than previous methods. The results of tuning the mathematical model to the field data show good agreement with the model prediction. Simple and robust explicit formulae are derived for the effective estimation of flow rate and thermal conductivity in gas wells. The proposed approach has been applied to determine the well gas rate and formation thermal conductivity from the acquired well pressure and temperature data in field A. It allows for recommending well stimulation of layers with low production rates.

Rim Sealing of Rotor-Stator Wheelspaces in the Absence of External Flow

1991 ◽  
Author(s):  
J. W. Chew ◽  
S. Dadkhah ◽  
A. B. Turner
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Reynolds Numbers ◽  
External Flow ◽  
Rotating Disc ◽  
Different Types ◽  
The Mathematical Model

Sealing of the cavity formed between a rotating disc and a stator in the absence of a forced external flow is considered. In these circumstances the pumping action of the rotating disc may draw fluid into the cavity through the rim seal. Minimum cavity throughflow rates required to prevent such ingress are estimated experimentally and from a mathematical model. The results are compared with other workers’ measurements. Measurements for three different types of rim seal are reported for a range of seal clearances and for rotational Reynolds numbers up to 3 × 106. The mathematical model is found to correlate the experimental data reasonably well.

FPGA-Based Design of P-Detection 1-Persistent CSMA Control System

2014 ◽  
Vol 602-605 ◽  
pp. 933-936 ◽  
Author(s):  
Zheng Gang Liu ◽  
Hong Wei Ding ◽  
Jia Long Xiong ◽  
Qian Lin Liu ◽  
Xiao Hui Ma
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
System Performance ◽  
Communication Protocol ◽  
Test Results ◽  
Fpga Design ◽  
Simulation Results ◽  
Communication Control ◽  
The Mathematical Model ◽  
Waveform Simulation

In this paper, we propose P-detection and 1-Persistent CSMA/CA protocol. Using average cycle method, we established the mathematical model of the protocol. Through derivation, we obtain the throughput expression of this protocol. Simulation results show that this protocol improves the throughput and it is effective to enhance the system performance. Using this protocol, we completed the FPGA design of communication control system in WSN. The product passed waveform simulation and it is downloaded to the DB2 platform. Test results confirm the throughput of system has been increased, achieving the improvement of communication protocol for WSN.

Chaotic Phenomena Induced by the Fast Plastic Deformation of Metals During Cutting

2005 ◽  
Vol 73 (2) ◽  
pp. 240-245 ◽  
Author(s):  
Zoltan Palmai
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Shear Stress ◽  
General Structure ◽  
Equation System ◽  
Qualitative Description ◽  
Balance Equations ◽  
Different Types ◽  
Energy Equations ◽  
The Mathematical Model

In the present study the examination of chip formation is focused on the primary shear zone, which is divided into two layers, and the variation of shear stress and temperature in time are given by two mechanical balance equations and three energy equations. All the five evolution differential equations are autonomous and nonlinear. The material characteristics are determined by an exponential constitutive equation. The mathematical model is suitable for the qualitative description of different types of chips, such as continuous chips and periodic or aperiodic shear localized chips, which is demonstrated by the general structure and typical solutions of the equation system.

scholarly journals DEVELOPMENT OF A MATHEMATICAL MODEL FOR THE RESEARCH OF THE DYNAMICS OF VIBRATION MILL WITH TWO DRIVES FOR BULK MATERIALS FINE GRINDING

2021 ◽  
pp. 89-99
Author(s):  
Volodymyr Topilnytskyy ◽  
Dariya Rebot
Keyword(s):  
Mathematical Model ◽  
Optimal Designs ◽  
High Tech ◽  
Bulk Materials ◽  
Fine Grinding ◽  
Different Types ◽  
Parameterized Model ◽  
The Mathematical Model ◽  
Universal Equipment ◽  
Vibration Mill

Reducing by grinding the size of various materials as raw materials for its further use is an urgent applied task. The requirements for the final product obtained by fine grinding are its homogeneity in shape and size of individual parts. It is necessary to reduce the time of the grinding operation, reduce energy consumption to obtain a unit of product of the required quality. One way to solve the problem is to use high-tech universal equipment, namely mills for fine grinding of materials. One way to solve the given problem is to use high-tech universal equipment, namely mills for fine grinding of materials. Their optimal design, construction, manufacture and operation are ensured by studying their dynamics at the stage of their development. In particular, such a study of the dynamics can be carried out on the basis of previously created mathematical models of these mills. The use of computer technology and appropriate mathematical CAD systems will speed up and optimize the process of studying the dynamics of the corresponding mill of fine grinding of materials. The purpose of the research is to build a mathematical nonlinear parameterized model of vibrating mill with two drives for bulk materials fine grinding for further study on its basis the dynamics of the mill with the development of optimal designs for mills with similar structure and the principle of operation and selection of optimal modes of operation. The mathematical model is presented as a system of expressions describing the of the mill points motion, which will include in the form of symbolic symbols all its parameters (kinematic, geometric, dynamic, force). This model is constructed using the Lagrange equation of the second kind and asymptotic methods of nonlinear mechanics. The mathematical model for studying of the dynamics of vibration mill with two drives for bulk materials fine grinding is nonlinear and universal. The non linearity of the model makes it possible to adequately determine of the above parameters influence on the amplitude of oscillations of the mill working chamber as the main factor in the intensity in the technological process of the fine grinding bulk materials fine grinding. The possibility of a wide range of changes in the parameters of the mill in the obtained models makes it universal based on the possibility of application for the study of dynamic processes in vibrating mills of different types with two or one drive which are different by shape, size, location of the suspension and more. This model can also be used to develop optimal designs for vibrating mills for different industries, which will be used to grind different types of materials in different volumes and productivity.

scholarly journals Validation of friction factor predictions in vertical slurry flows with coarse particles

2020 ◽  
Vol 68 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Artur Bartosik
Keyword(s):  
Mathematical Model ◽  
Reynolds Number ◽  
Friction Factor ◽  
Particle Diameter ◽  
Solid Particles ◽  
Coarse Particles ◽  
Carrier Liquid ◽  
Different Types ◽  
Slurry Flows ◽  
The Mathematical Model

AbstractThe paper presents validation of a mathematical model describing the friction factor by comparing the predicted and measured results in a broad range of solid concentrations and mean particle diameters. Three different types of solids, surrounded by water as a carrier liquid, namely Canasphere, PVC, and Sand were used with solids density from 1045 to 2650 kg/m3, and in the range of solid concentrations by volume from 0.10 to 0.45. All solid particles were narrowly sized with mean particle diameters between 1.5 and 3.4 mm. It is presented that the model predicts the friction factor fairly well. The paper demonstrates that solid particle diameter plays a crucial role for the friction factor in a vertical slurry flow with coarse solid particles. The mathematical model is discussed in reference to damping of turbulence in such flows. As the friction factor is below the friction for water it is concluded that it is possible that the effect of damping of turbulence is included in the KB function, which depends on the Reynolds number.

scholarly journals Wear issues of pumping units

2021 ◽  
Vol 264 ◽  
pp. 04081
Author(s):  
Oybek Ishnazarov ◽  
Abdusaid Isakov ◽  
Utkir Islomov ◽  
Umirzoq Xoliyorov ◽  
Dilshod Ochilov
Keyword(s):  
Mathematical Model ◽  
Wear Resistance ◽  
Service Life ◽  
Rotation Speed ◽  
Operating Mode ◽  
Factors Influencing ◽  
Pump Shaft ◽  
Pumping Unit ◽  
Pumping Units ◽  
The Mathematical Model

The article presents the possibility of increasing the service life of pumping units. Particular attention is paid to the regulation of the speed of rotation of the pumping unit. There are some assumptions in the mathematical model that do not affect the final result. The factors influencing the operating mode are given. It is indicated that the speed of rotation of the pump shaft significantly affects the wear resistance of the pump blades. Thus, the regulation of the pump rotation speed will rationally increase its service life.

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