scholarly journals Mathematical Model of the Piped Vehicle Motion in Piped Hydraulic Transportation of Tube-Contained Raw Material

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yongye Li ◽  
Xihuan Sun

The piped hydraulic transportation of tube-contained raw material is an emerging technique for transporting materials. In this technique, the piped vehicle is one of the core components, and its motion characteristics directly determine the transportation energy consumption and the transportation cost of this technique. To study the motion characteristics of the piped vehicle, the force of the piped vehicle was analyzed from the mechanical perspective in this paper. On the assumption that the piped vehicle moved steadily and it had sufficient stiffness, the mathematical model of the piped vehicle motion was established in the turbulent flow according to the stress characteristics of the piped vehicle and the factors influencing its motion characteristics, and then the mathematical model was tested by experiments. The findings show that the calculated values of the velocities of the piped vehicle were identical to the experimental values with changes in various influencing factors. When the flow discharge, the diameter or length of the piped vehicle increased, or the mass of transported material decreased, the velocity of the piped vehicle increased. The maximum relative error did not exceed 9.47%, which proved that the mathematical model of the piped vehicle motion was rational. The results can provide theoretical basis to improve the structure of the piped vehicle and the piped hydraulic transportation technique of tube-contained raw material.

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Delia Perju ◽  
Harieta Pirlea ◽  
Gabriela-Alina Brusturean ◽  
Dana Silaghi-Perju ◽  
Sorin Marinescu

The European laws and recently the Romanian ones impose more and more strict norms to the large nitrogen dioxide polluters. They are obligated to continuously improve the installations and products so that they limit and reduce the nitrogen dioxide pollution, because it has negative effects on the human health and environment. In this paper are presented these researches made within a case study for the Timi�oara municipality, regarding the modeling and simulation of the nitrogen dioxide dispersion phenomenon coming from various sources in atmosphere with the help of analytical-experimental methods. The mathematical model resulting from these researches is accurately enough to describe the real situation. This was confirmed by comparing the results obtained based on the model with real experimental values.


2015 ◽  
Vol 14 (2) ◽  
pp. 90 ◽  
Author(s):  
K. L. M. Dos Passos ◽  
B. M. Viegas ◽  
E. N. Macêdo ◽  
J. A. S. Souza ◽  
E. M. Magalhães

The use of the waste of the Bayer process, red mud, is due to its chemical and mineralogical composition that shows a material rich in oxides of iron, titanium and aluminum. Some studies conducted show that this waste can be applied as a source of alternative raw material for concentration and subsequent recovery of titanium compounds from an iron leaching process, which is present in higher amounts, about 30% by weight. To obtain a greater understanding about the leaching kinetics, the information of the kinetic data of this process is very important. In this context, the main objective of this work is the development of a mathematical model that is able to fit the experimental data (conversion / extraction iron, titanium and aluminum) of the leaching process by which is possible to obtain the main kinetic parameters such as the activation energy and the velocity of chemical reactions as well as the controlling step of the process. The development of the mathematical model was based on the model of core decreasing. The obtained model system of ordinary differential equations was able to fit the experimental data obtained from the leaching process, enabling the determination of the controlling step, the rate constants and the activation energies of the leaching process.


DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 155-162
Author(s):  
Ageu Araujo Machado ◽  
João Carlos Zayatz ◽  
Marcos Meurer Da Silva ◽  
Guilherme Melluzzi Neto ◽  
Gislaine Camila Lapasini Leal ◽  
...  

This study aims to optimize the one-dimensional cutting process of aluminum bars for the production of aluminum doors. Reducing the use of bars and the amount of material that becomes scrap is a key factor in process efficiency, reducing the need for raw material procurement. The mathematical model used considers the size of the bar, the number and size of cuts, the size of the leftovers that can be used and the size of the leftovers that are considered scrap. Based on real data from a company in the aluminum frame segment, the mathematical model was used to simulate three different scenarios. Three different objective functions were used in the simulations, and the results obtained in each scenario were described in order to indicate the advantages and disadvantages of using each objective function. For the instance sizes studied, the model is able to obtain optimal solutions with little computational time.


Author(s):  
R. Rajita Shenoi ◽  
P. Krishnankutty ◽  
R. Panneer Selvam

The examination of maneuvering qualities of a ship is necessary to ensure its navigational safety and prediction of trajectory. The study of maneuverability of a ship is a three-step process, which involves selection of a suitable mathematical model, estimation of the hydrodynamic derivatives occurring in the equation of motion, and simulation of the standard maneuvering tests to determine its maneuvering qualities. This paper reports the maneuvering studies made on a container ship model (S175). The mathematical model proposed by Son and Nomoto (1981, “On Coupled Motion of Steering and Rolling of a High Speed Container Ship,” J. Soc. Nav. Arch. Jpn., 150, pp. 73–83) suitable for the nonlinear roll-coupled steering model for high-speed container ships is considered here. The hydrodynamic derivatives are determined by numerically simulating the planar motion mechanism (PMM) tests in pure yaw and combined sway–yaw mode using an Reynolds-Averaged Navier–Stokes Equations (RANSE)-based computational fluid dynamics (CFD) solver. The tests are repeated with the model inclined at different heel angles to obtain the roll-coupled derivatives. Standard definitive maneuvers like turning tests at rudder angle, 35 deg and 20 deg/20 deg zig-zag maneuvers are simulated using the numerically obtained derivatives and are compared with those obtained using experimental values.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Honghuan Yin ◽  
Hongbin Yu ◽  
Junqiang Peng ◽  
Hongyu Shao

In this paper, the transmission process of the heald frame driven by the dobby is analyzed. The equivalent motion model of the dobby modulator, the eccentric mechanism, and the motion transmission unit are constructed. Then, based on the given movement characteristics of the heald frame, the mathematical model is built to achieve the cam pitch curve and the cam profile of the modulator. The numerical solution method for this is developed. The preparation of a mathematical model for the new concept of the solving cam profile based on the motion characteristics of heald frames is explained in this study. By setting a 11th polynomial motion law of the heald frame, due to the inconsistency between the outward and return motion laws of the crank-rocker mechanism, an asymmetrical cam profile is obtained under the premise of ensuring that the heald frame’s ascending and descending motions are consistent. Through the kinematics simulation analysis, the correctness of the reverse process is verified.


Author(s):  
Aurelija Kemzūraitė ◽  
Algirdas Raila ◽  
Kristina Bimbiraitė ◽  
Olga Kornyšova ◽  
Audrius Maruška

Medicinal herbs after their harvesting participate in heat exchange with the environmental, as does each organic and hygroscopic material. Drying helps to conserve the medicinal raw material with the maximal preservation of its quality. The present investigation deals with the influence of the surrounding air factors (temperature and relative humidity) on drying intensity. The study object was aboveground part of hyssop (Hyssopus officinalis L.), i.e. Hyssopi herba was used as medicinal raw material. The aim of the study was to offer a mathematical model of time‐related medicinal herbs moisture dynamics and to show its qualitative agreement with the physical model of diffusion as well as to determine the optimum ventilation intensity of medicinal herbs. Drying of Hyssopi herba using active ventilation was investigated. Ventilation intensity and the parameters of the drying agent influenced the processes of moisture dynamics, the total drying time and the quality of Hyssopi herba. The basic prerequisites of the drying process have been analysed. A mathematical model of moisture dynamics has been proposed and used to show the dependence of theoretical moisture dynamics on ventilation velocity. The obtained experimental values of moisture content dynamics during the drying of Hyssopi herba have been shown to agree with theoretical dependences. Santrauka Vaistiniai augalai, kaip ir kiekviena organinė higroskopinė medžiaga, dalyvauja šilumos mainų procese su aplinka. Džiovinant siekiama konservuoti vaistinius augalus iki reikiamo drėgnio, kiek įmanoma išsaugant jų kokybę. Nagrinėta aplinkos oro veiksnių (temperatūros ir santykinio oro drėgnio) įtaka džiovinimo intensyvumui. Tyrimams naudota antžeminė vaistinio isopo (Hyssopus officinalis L.) dalis, t. y. vaistinė augalinė žaliava – isopų žolė (Hyssopi herba). Tyrimų tikslas – sudaryti drėgmės kitimo per tam tikrą laiką matematinį modelį, taikant gautą difuzijos sprendinį, bei nustatyti optimalų ventiliavimo intensyvumą. Tirtas Hyssopi herba džiovinimo taikant aktyviąją ventiliaciją procesas. Išanalizavus pagrindines džiovinimo sąlygas, sudarytas drėgmės kitimo priklausomybės nuo ventiliavimo intensyvumo, matematinis modelis. Ventiliavimo intensyvumas ir džiovinimo agento parametrai turėjo įtakos drėgmės mainų procesams, džiovinimo trukmei ir vaistinės augalinės žaliavos kokybei. Gauti drėgnio kitimo džiovinant Hyssopi herba rezultatai patvirtino, kad teorinės priklausomybės kokybiškai atitinka tiriamąjį procesą. Резюме Лекарственные растения, как и всякий органический гигроскопический материал, участвуют в процессе теплообмена с окружающей средой. С помощью сушки требуется консервировать лекарственные растения до нужной влажности, максимально сохраняя их качествo. Исследовалось влияние температуры и относительной влажности окружающего воздуха на интенсивность сушки. Объект исследования – наземная часть лекарственного иссопа (Hyssopus officinalis L.), т.е. лекарственное сырьё Hyssopi herba. Целью исследования было создать математическую модель изменения влажности с течением времени, применяя полученное решение диффузии, и определить оптимальную интенсивность вентиляции. Процесс сушки Hyssopi herba исследовался способом активной вентиляции. Различные параметры интенсивности вентиляции и сушильной среды влияли на процесс влагообмена, продолжительность сушки и качество лекарственного сырья. Произведен качественный анализ основных предпосылок процесса сушки. Предложена математическая модель изменения влажности, и на ее основе получена теоретическая зависимость изменения влажности от интенсивности вентиляции. Полученные результаты подтвердили соответствие между теоретической моделью и экспериментальными данными.


Author(s):  
Intaek Gong ◽  
Kyungho Lee ◽  
Jaewon Kim ◽  
Yunhong Min ◽  
Kwang Sup Shin

A lot of previous research have proposed various frameworks and algorithms to optimize routes to reduce the total transportation cost, which accounts for over 70% of overall logistics cost. However, it is very hard to find the cases applied the mathematical models or algorithms to the practical business environment cases, especially daily operating logistics services like convenient stores. Most of previous research have considered the developing an optimal algorithm which can solve the mathematical problem within the practical time while satisfying all constraints such as the capacity of delivery and pick-up, and time windows. For the daily pick-up and delivery service like supporting several convenient stores, it is required to consider the unit transporting container as well as the demand, capacity of trucks, traveling distance and traffic congestion. Especially, the reusable transporting container, trays, should be regarded as the important asset of logistics center. However, if the mathematical model focuses on only satisfying constraints related delivery and not considering the cost of trays, it is often to leave the empty trays on the pick-up points when there is not enough space in the track. In this research, it has been proposed to build the mathematical model for optimizing pick-up and delivery plans by extending the general vehicle routing problem of simultaneous delivery and pickup with time windows while considering left-over cost. With the numerical experiments, it has been proved that the proposed model may reduce the total delivery cost. It may be possible to apply the proposed approach to the various logistics business which uses the reusable transporting container like shipping containers, refrigerating containers, trays, and pallets.


1977 ◽  
Vol 47 (5) ◽  
pp. 311-316
Author(s):  
Nelson P. C. Chao

A mathematical model is provided to describe the thin-layer liquid film thickness on the surface of a rotating roll which is partially immersed in a liquid bath. The equation expresses the initial film thickness in terms of roll speed and immersion depth as well as liquid viscosity, surface tension, and density. The roll speed and liquid viscosity are the two dominant parameters affecting the film thickness. An x-ray backscattering technique was used to measure the film thickness. An important feature of this technique is that it permits the measurements to be carried out under a steady-state condition without disturbing the liquid film and the roll. The principle of a portable instrument and the technique involved in the measurements are described. Within the scope of the present investigation with Newtonian liquid and laminar flow, the experimental values of film thickness determined by the x-ray backscattering technique agreed very well with the theoretical values predicted by the mathematical model.


2012 ◽  
Vol 178-181 ◽  
pp. 838-842
Author(s):  
Gui Hua Sheng ◽  
Quan Cheng Zhou

An optimal condition of supercritical fluid extraction (SFE) for genistein in extruded soybean was developed. Optimal conditions through quadratic orthogonal rotation design were verified. The results from SC – CO2 showed that all five experiment factors tested have significant effects on the yield of genistein. The mathematical model set had close agreements with experimental values. It was found that there were 32 optimal extract conditions under which genistein yield higher than 0.092% were gotten through simulate compute. The optimal extracting conditions were stable and recurrable. SC–CO2 had a potential in the extraction of genistein from extruded soybean products.


2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Andreia F. S. Genaro ◽  
Ezio C. Garcia ◽  
Issamu Muraoka ◽  
Kevin E. de Conde

This paper presents results of the research investigation regarding the causes for temperature variation of the SCD-1 (data-collection satellite) by analyzing its thermal behavior evolution throughout 13 years in orbit. SCD-1, the first satellite designed and built in Brazil, was launched in 1993 and is still in operation. A mathematical model has been developed to simulate thermal behavior of SCD-1 in orbit, which was used as a working tool during project design phase, and is presented here. Temperatures of SCD-1 in orbit have been monitored and recorded in the Control and Tracking Center (São José dos Campos, SP, Brazil) since its launch. An analysis carried out at the mission’s beginning showed that all the temperatures were within the ranges predicted in model. Over the years, the battery, which is the most temperature-sensitive equipment in the satellite, had an increase in temperature approaching upper limit. A method has been developed to investigate the causes of this upswing in which an optimization routine linked to the mathematical model corrects a selected set of parameters in order to adjust the theoretical temperature values to the experimental values. By means of this methodology, data from SCD-1 were analyzed from 1995 to 2005 period and it was concluded that the rise in temperature was caused by an increase in internal battery heat dissipation and absorptivity in solar spectrum of some of the external satellite shielding, both consequences of a long-term degradation.


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