The flow in industrial cyclones

1987 ◽  
Vol 178 ◽  
pp. 507-519 ◽  
Author(s):  
M. I. G. Bloor ◽  
D. B. Ingham
Keyword(s):  
Mathematical Model ◽  
Closed Form ◽  
Secondary Flows ◽  
Experimental Investigations ◽  
Main Body ◽  
Simple Mathematical Model ◽  
Good Agreement

A simple mathematical model for the flow in a conical cyclone is developed which allows solutions to be obtained in closed form. The flow in the main body of the cyclone is regarded as inviscid but the nature of the fluid entry to the device and the conical geometry ensure that secondary flows develop which make the flow highly rotational. The results of the theory are compared with data from two quite different experimental investigations, and good agreement is obtained.

scholarly journals A Simple Mathematical Model of Cyclic Circadian Learning

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
J. Šimon ◽  
M. Bulko
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Learning Process ◽  
Memory Retention ◽  
Simple Mathematical Model ◽  
Prior Learning ◽  
Mnemonic Devices ◽  
Concurrent Processes ◽  
Mathematical Operations ◽  
Good Agreement

This paper deals with the derivation of a simple mathematical model of cyclic learning with a period of 24 hours. Various requirements are met with an emphasis and approach which relies on simple mathematical operations, the prediction of measurable quantities, and the creation of uncomplicated processes of calibration. The presented model can be used to answer questions such as the following.Will I be able to memorize a given set of information? How long will it take to memorize information? How long will I remember the information that was memorized?The model is based on known memory retention functions that are in good agreement with experimental results. By the use of these functions and by formalism of differential equations, the concurrent processes of learning and forgetting are described mathematically. The usability of this model is limited to scenarios where logical bonds (connections to prior learning) are not created and mnemonic devices cannot be utilized during the learning process.

Statistical Energy Analysis for Electronic Equipment

1991 ◽  
Vol 113 (3) ◽  
pp. 322-325
Author(s):  
L. Lu
Keyword(s):  
Mathematical Model ◽  
High Frequency ◽  
Vibration Analysis ◽  
Energy Analysis ◽  
Element Model ◽  
Electronic Equipment ◽  
System Response ◽  
Statistical Energy Analysis ◽  
Simple Mathematical Model ◽  
Good Agreement

Vibration response of electronic equipment analyzed by a simple mathematical model or a finite element model can only provide a limited system response calculation. Application of the Statistical Energy Analysis (SEA) was extended to the calculation of the vibrations of individual components. In order to demonstrate the applicability of SEA to instrumentation vibration analysis at high frequency ranges, an 8-component electronic box was chosen for test and analysis. There was good agreement between tested and analytical results in the frequency averaged sense.

Infrasound and Low Frequency Noise in the Passenger Compartment of Vehicles

1997 ◽  
Vol 16 (4) ◽  
pp. 219-227 ◽  
Author(s):  
Helmut Spannheimer ◽  
Raymond Freymann
Keyword(s):  
Mathematical Model ◽  
Low Frequency ◽  
Experimental Investigations ◽  
Frequency Noise ◽  
Simple Mathematical Model ◽  
Low Frequency Noise ◽  
Acoustic Response ◽  
Frequency Range ◽  
Passenger Compartment

The acoustic response determined in the passenger compartment of a vehicle is characterized by resonances in the infrasound and low frequency range. A simple mathematical model is derived allowing the numerical identification of the related low frequency acoustic eigenmodes. The numerically obtained results are verified on the basis of experimental investigations.

On the Main Flow Pattern in Hydrocyclones

1993 ◽  
Vol 115 (1) ◽  
pp. 21-25 ◽  
Author(s):  
C. C. Hwang ◽  
H. Q. Shen ◽  
G. Zhu ◽  
M. M. Khonsari
Keyword(s):  
Theoretical Model ◽  
Flow Field ◽  
Closed Form ◽  
Flow Pattern ◽  
Main Flow ◽  
Experimental Measurements ◽  
Main Body ◽  
Governing Equations ◽  
Adequate Representation ◽  
Good Agreement

A theoretical model is developed for the prediction of the main flow pattern in hydrocyclones. The model regards the main body of the cyclone as inviscid and includes provisions for the fluid underflow in cyclones. The governing equations are solved analytically in closed form. To verify the results, a laboratory-scale conically-shaped hydrocyclone was designed, built, and tested. Experimental measurements for axial and tangential velocities are presented with a series of tests solely devoted to the effect of underflow. The theoretical and experimental results are shown to be in good agreement. It is concluded that such an inviscid model gives an adequate representation of the main flow field in a cyclone.

Packing Effect on the Transfer Integrals and Mobility in α,α′-bis(dithieno[3,2-b:2′,3′-d]thiophene) (BDT) and its Heteroatom-Substituted Analogues

2011 ◽  
Vol 64 (12) ◽  
pp. 1587 ◽  
Author(s):  
Ahmad Irfan ◽  
Abdullah G. Al-Sehemi ◽  
Shabbir Muhammad ◽  
Jingping Zhang
Keyword(s):  
Electron Transfer ◽  
Electron Mobility ◽  
Hole Mobility ◽  
Experimental Investigations ◽  
Hole Transfer ◽  
Space Group ◽  
Space Groups ◽  
Transfer Integrals ◽  
Packing Effect ◽  
Good Agreement

Theoretically calculated mobility has revealed that BDT is a hole transfer material, which is in good agreement with experimental investigations. The BDT, NHBDT, and OBDT are predicted to be hole transfer materials in the C2/c space group. Comparatively, hole mobility of BHBDT is 7 times while electron mobility is 20 times higher than the BDT. The packing effect for BDT and designed crystals was investigated by various space groups. Generally, mobility increases in BDT and its analogues by changing the packing from space group C2/c to space groups P1 or . In the designed ambipolar material, BHBDT hole mobility has been predicted 0.774 and 3.460 cm2 Vs–1 in space groups P1 and , which is 10 times and 48 times higher than BDT (0.075 and 0.072 cm2 Vs–1 in space groups P1 and ), respectively. Moreover, the BDT behaves as an electron transfer material by changing the packing from the C2/c space group to P1 and .

scholarly journals Validation of MATLAB algorithm to implement a two-step parallel pyrolysis model for the prediction of maximum %char yield

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Ibiba Taiwo Horsfall ◽  
Macmanus Chinenye Ndukwu ◽  
Fidelis Ibiang Abam ◽  
Ololade Moses Olatunji ◽  
Ojong Elias Ojong ◽  
...  
Keyword(s):  
Experimental Data ◽  
Isothermal Condition ◽  
Char Yield ◽  
Experimental Investigations ◽  
Time Saving ◽  
Pyrolysis Products ◽  
Pyrolysis Model ◽  
Experimental Yield ◽  
By Products ◽  
Good Agreement

AbstractNumerical modeling of biomass pyrolysis is becoming a cost and time-saving alternative for experimental investigations, also to predict the yield of the by-products of the entire process. In the present study, a two-step parallel kinetic model was used to predict char yield under isothermal condition. MATLAB ODE45 function codes were employed to solve a set of differential equations that predicts the %char at varying residence times and temperatures. The code shows how the various kinetic parameters and mass of pyrolysis products were determined. Nevertheless, the algorithm used for the prediction was validated with experimental data and results from past works. At 673.15 K, the numerical simulation using ODE45 function gives a char yield of 27.84%. From 573.15 K to 673.15 K, char yield ranges from 31.7 to 33.72% to 27.84% while experimental yield decreases from 44 to 22%. Hence, the error between algorithm prediction and experimental data from literature is − 0.26 and 0.22. Again, comparing the result of the present work with the analytical method from the literature showed a good agreement.

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