Ujjwal Kumar Deb | Chittagong University of Engineering & Technology (CUET) (original) (raw)

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Papers by Ujjwal Kumar Deb

Research paper thumbnail of Simulation of Load Absorption and Deflection of Helical Suspension Spring: A Case of Finite Element Method

Intelligent Computing & Optimization

Research paper thumbnail of Effects of crack location and depths for an iron bar: A Finite Element approach

Materials Today: Proceedings

Research paper thumbnail of The Growth Factors Involved in Microalgae Cultivation for Biofuel Production: A Review

Computational Water, Energy, and Environmental Engineering

Research paper thumbnail of Modeling and Simulation of a Cracked Beam with Different Location Using FEM

Computational Water, Energy, and Environmental Engineering

Research paper thumbnail of The Effect of Irradiance Related Temperature on Microalgae Growth in a Tubular Photo Bioreactor for Cleaner Energy

American Journal of Computational Mathematics, 2017

In microalgae based biofuel technology, the light is one of the important factors for the proper ... more In microalgae based biofuel technology, the light is one of the important factors for the proper growth of microalgae cells as microalgae is a photosynthetic microorganism. For a large scale outdoor culture the irradiance of sunlight and associated temperature is also need to consider. In this study aims to present computational model of microalgae growth taking effect of solar irradiance and corresponding temperature in a tubular photo bioreactor for an outdoor culture system. We consider the transient behavior of temperature inside the photo bioreactor for a microalgae culture. The optimum range of temperature for outdoor cultivation of microalgae is about 22˚C-27˚C and out of this range the microalgae cell growth inhibits. Many correlations have already been established to investigate the algal productivity based on the dynamic conditions of temperature in case of full scale outdoor cultivation. However, none of them are validated yet numerically considering the model as a function of weather conditions, operational behavior and design criteria. A tubular photobioreactor (PBR) with length 20.5 m and radius 0.05 m has taken account as a simulation model. The PBR is horizontally placed as temperature variations can be observed with greater accuracy. As the solar irradiance varies at any geographic latitude for a year and so thus temperature, equations and parameters are established relating the irradiance with the temperature to simulate the effect. We observed some significant effects of temperature on the growth of microalgae. Moreover, for the maximum growth of the cells we should control the surrounding temperature.

Research paper thumbnail of The effect of the angle of perforation on perforated inserts in a pipe flow for heat transfer analysis

Mathematics and Computers in Simulation

Research paper thumbnail of Simulation of heat transfer in a tubular U-loop pipe using the rectangular inserts and without insert

Research paper thumbnail of Augmentation of Heat Transfer in Pipe Flow Using Plain Twisted Tape Inserts for Different Twist Ratios

Energy and Power Engineering

The heat transfer augmentation of plain twisted tape inserts for different twist ratios has been ... more The heat transfer augmentation of plain twisted tape inserts for different twist ratios has been studied in this study. The data are conducted using the plain twisted tape insert with five different twist ratios respectively. The range of Reynolds number is considered under a uniform heat flux condition. In the case of simulation, the tapes are made from a stainless steel strip with a thickness of 2 mm. A tubular pipe with 850 mm U-loop length and twist length of 800 mm each is considered in our study for simulation. Water is used as working fluids inside the tube for our simulation. The simulation results demonstrate that the important heat transfer parameters including Nusselt number (Nu), friction factor (f) and thermal performance index (η) are gradually increased with the increment of the twist ratio and reached at the saturated level while twist ratio is 3.5, afterward the thermal properties are decreased.

Research paper thumbnail of Investigation of Flow Dynamics for a Microalgae Suspension in an Open Pond System

American Journal of Computational Mathematics

In the microalgae based biofuel technology, two main cultivation methods are available such as th... more In the microalgae based biofuel technology, two main cultivation methods are available such as the Open pond system and the Closed photo bioreactor (PBR). The primary advantages of utilizing open raceway ponds are low production and maintenance cost. Though the open raceway ponds have been adjudged potentially cost effective, so many surrounding issues are involved to produce microalgae at a large scale that could make microalgae fuel cost competitive with the conventional petro oil. Many researchers have been studied so far to increase the efficiency of the cultivation methods without providing a proper mathematical model of flow dynamics inside the open raceway ponds. This paper presents a mathematical model to analyze the flow behavior of an open pond culture focusing the mixing factors by using a paddlewheel while the paddlewheel have its own unique dynamic characteristics. From our simulation we observed that the paddlewheel plays a vital role in mixing and the growth of microalgae. The velocity profiles, shear stress distributions are also studied at different parts of an open pond culture for a microalgae suspension.

Research paper thumbnail of Simulation of temperature effect on microalgae culture in a tubular photo bioreactor for local solar irradiance

Research paper thumbnail of Computational Modeling and Dynamics of the Oil and Water Flow Using the Galerkin Approximation

American Journal of Computational Mathematics

A Computational Fluid Dynamic (CFD) model is presented to analyze the flow dynamics of a two phas... more A Computational Fluid Dynamic (CFD) model is presented to analyze the flow dynamics of a two phase incompressible flow in the application sectors of different industries. The Finite Element method (FEM) which is based on the Galerkin approximation, has been implemented for this two phase flow model. Generally, two-phase flows can occur in different forms like gas-liquid, liquid-liquid and solid-liquid forms. The Oil and Water two-phase flow is an important phenomenon in petroleum industry for crude oil production and transportation. In our study, a laminar flow of liquid-liquid phase is considered to simulate the flow dynamics where the liquid phases are water and oil. The COMSOL Multiphysics software is used to perform the simulation including velocity profile, volume fraction, shear rate, pressure distributions and interfacial thicknesses at different times. A typical circular tube domain with radius 0.05 m and length 8 m is assumed for our simulation.

Research paper thumbnail of Comparative Analysis of Hydrodynamics Behavior of Microalgae Suspension Flow in Circular, Square and Hexagonal Shape Photo Bioreactors

American Journal of Computational Mathematics, 2016

Microalgae based biofuel is an emerging natural source of energy alternative to the fossil fuel. ... more Microalgae based biofuel is an emerging natural source of energy alternative to the fossil fuel. As microalgae are photosynthetic microorganisms, light is one of the limiting factors for its culture. Though many researches have been carried out for findings behind suitable culture system for the proper growth of microalgae, those are confined only to tubular Photo-bioreactor (PBR). This paper aims to make comparison among the horizontal loop photo bioreactors with different cross sections based on the analysis of hydrodynamics behavior. Three different geometrical shapes having vertical cross sections of circular, square and hexagonal PBR, have been proposed taking into account light intensity for microalgae culture. In this study, we simulate the flow dynamics of three types of PBRs and discuss the velocity, pressure and shear stress properties as microalgae endurance capacity depends on them. For the dimension of the three PBRs we considered here, each of them have radius of about 0.05 m while the length together with bending portion is approximately 20.5 m for a single loop. From the study, the hydrodynamic behaviors are observed to be quite dissimilar in case of three PBR's. In the straight portion the velocity profile is quite parabolic in tubular but distorted minimally in case of square and hexagonal PBRs. In the middle of the U-loop, a haphazard fluid distribution is noticed. The velocity magnitude and agitation of microalgae cells are higher in hexagonal than in square and tubular. The shear rate is less in case of tubular compared to square and hexagonal. A linear pressure drop is found from the inlet to the outlet for three PBR's. From this comparison, it can be said that the tubular one would be the best option for microalgae culture in case of industrial purposes.

Research paper thumbnail of Numerical Simulation of Two-phase Laminar Flow for CO 2 and Microalgae Suspension in the HLTP

This paper proposes a mathematical model of two-phase flow for carbon-dioxide and microalgae susp... more This paper proposes a mathematical model of two-phase flow for carbon-dioxide and microalgae suspension in an Horizontal Loop Tubular Photo-bioreactor (HLTP) taking into account the light irradiance. The model
with no-slip condition on the wall and zero outward normal stress at the outlet of the HLTP is used to simulate
the fluid phenomena inside the HLTP. The viscosity of the algal suspension is considered as a function of relative
viscosity related to concentration and growth rate of the microalgae. The simulation is carried out on the seventh
day of the culture. The effect of average irradiance in a day on the viscosity is investigated. The results show that
the two-phase flow model can capture the real behavior of the microalgae culture in the HLTP.

Research paper thumbnail of The Enhancement of Heat Transfer in a Circular Tube with Insert and without Insert by Using the Finite Element Method

Procedia Engineering, 2015

Research paper thumbnail of INTERNATIONAL JOURNAL OF MATHEMATICS AND COMPUTERS IN SIMULATION Comparison of Single-phase and Two-phase Flow Dynamics in the HLTP for Microalgae Culture

This paper aims to show dynamic behavior of microalgae suspension in a Horizontal Loop Tubular Ph... more This paper aims to show dynamic behavior of microalgae suspension in a Horizontal Loop Tubular Photobioreactor (HLTP). Two models of a single-phase flow and a two-phase flow have been proposed taking into account the light irradiance. The governing equations describing a single-phase flow are the continuity equation and the Navier-Stokes equation. The viscosity of the microalgae suspension is a function of microalgae cell concentration which varies in time. Using the governing equations of a single-phase flow together with the Cahn-Hiliard mass conservation equation, we can describe the dynamic behavior of a two-phase flow. The results obtained from both models are compared. It is noted that both results are significantly different. In the two-phase flow model, the mass transfer rate and the shear rate are higher than those obtained from the single-phase model.

Research paper thumbnail of Simulation of Load Absorption and Deflection of Helical Suspension Spring: A Case of Finite Element Method

Intelligent Computing & Optimization

Research paper thumbnail of Effects of crack location and depths for an iron bar: A Finite Element approach

Materials Today: Proceedings

Research paper thumbnail of The Growth Factors Involved in Microalgae Cultivation for Biofuel Production: A Review

Computational Water, Energy, and Environmental Engineering

Research paper thumbnail of Modeling and Simulation of a Cracked Beam with Different Location Using FEM

Computational Water, Energy, and Environmental Engineering

Research paper thumbnail of The Effect of Irradiance Related Temperature on Microalgae Growth in a Tubular Photo Bioreactor for Cleaner Energy

American Journal of Computational Mathematics, 2017

In microalgae based biofuel technology, the light is one of the important factors for the proper ... more In microalgae based biofuel technology, the light is one of the important factors for the proper growth of microalgae cells as microalgae is a photosynthetic microorganism. For a large scale outdoor culture the irradiance of sunlight and associated temperature is also need to consider. In this study aims to present computational model of microalgae growth taking effect of solar irradiance and corresponding temperature in a tubular photo bioreactor for an outdoor culture system. We consider the transient behavior of temperature inside the photo bioreactor for a microalgae culture. The optimum range of temperature for outdoor cultivation of microalgae is about 22˚C-27˚C and out of this range the microalgae cell growth inhibits. Many correlations have already been established to investigate the algal productivity based on the dynamic conditions of temperature in case of full scale outdoor cultivation. However, none of them are validated yet numerically considering the model as a function of weather conditions, operational behavior and design criteria. A tubular photobioreactor (PBR) with length 20.5 m and radius 0.05 m has taken account as a simulation model. The PBR is horizontally placed as temperature variations can be observed with greater accuracy. As the solar irradiance varies at any geographic latitude for a year and so thus temperature, equations and parameters are established relating the irradiance with the temperature to simulate the effect. We observed some significant effects of temperature on the growth of microalgae. Moreover, for the maximum growth of the cells we should control the surrounding temperature.

Research paper thumbnail of The effect of the angle of perforation on perforated inserts in a pipe flow for heat transfer analysis

Mathematics and Computers in Simulation

Research paper thumbnail of Simulation of heat transfer in a tubular U-loop pipe using the rectangular inserts and without insert

Research paper thumbnail of Augmentation of Heat Transfer in Pipe Flow Using Plain Twisted Tape Inserts for Different Twist Ratios

Energy and Power Engineering

The heat transfer augmentation of plain twisted tape inserts for different twist ratios has been ... more The heat transfer augmentation of plain twisted tape inserts for different twist ratios has been studied in this study. The data are conducted using the plain twisted tape insert with five different twist ratios respectively. The range of Reynolds number is considered under a uniform heat flux condition. In the case of simulation, the tapes are made from a stainless steel strip with a thickness of 2 mm. A tubular pipe with 850 mm U-loop length and twist length of 800 mm each is considered in our study for simulation. Water is used as working fluids inside the tube for our simulation. The simulation results demonstrate that the important heat transfer parameters including Nusselt number (Nu), friction factor (f) and thermal performance index (η) are gradually increased with the increment of the twist ratio and reached at the saturated level while twist ratio is 3.5, afterward the thermal properties are decreased.

Research paper thumbnail of Investigation of Flow Dynamics for a Microalgae Suspension in an Open Pond System

American Journal of Computational Mathematics

In the microalgae based biofuel technology, two main cultivation methods are available such as th... more In the microalgae based biofuel technology, two main cultivation methods are available such as the Open pond system and the Closed photo bioreactor (PBR). The primary advantages of utilizing open raceway ponds are low production and maintenance cost. Though the open raceway ponds have been adjudged potentially cost effective, so many surrounding issues are involved to produce microalgae at a large scale that could make microalgae fuel cost competitive with the conventional petro oil. Many researchers have been studied so far to increase the efficiency of the cultivation methods without providing a proper mathematical model of flow dynamics inside the open raceway ponds. This paper presents a mathematical model to analyze the flow behavior of an open pond culture focusing the mixing factors by using a paddlewheel while the paddlewheel have its own unique dynamic characteristics. From our simulation we observed that the paddlewheel plays a vital role in mixing and the growth of microalgae. The velocity profiles, shear stress distributions are also studied at different parts of an open pond culture for a microalgae suspension.

Research paper thumbnail of Simulation of temperature effect on microalgae culture in a tubular photo bioreactor for local solar irradiance

Research paper thumbnail of Computational Modeling and Dynamics of the Oil and Water Flow Using the Galerkin Approximation

American Journal of Computational Mathematics

A Computational Fluid Dynamic (CFD) model is presented to analyze the flow dynamics of a two phas... more A Computational Fluid Dynamic (CFD) model is presented to analyze the flow dynamics of a two phase incompressible flow in the application sectors of different industries. The Finite Element method (FEM) which is based on the Galerkin approximation, has been implemented for this two phase flow model. Generally, two-phase flows can occur in different forms like gas-liquid, liquid-liquid and solid-liquid forms. The Oil and Water two-phase flow is an important phenomenon in petroleum industry for crude oil production and transportation. In our study, a laminar flow of liquid-liquid phase is considered to simulate the flow dynamics where the liquid phases are water and oil. The COMSOL Multiphysics software is used to perform the simulation including velocity profile, volume fraction, shear rate, pressure distributions and interfacial thicknesses at different times. A typical circular tube domain with radius 0.05 m and length 8 m is assumed for our simulation.

Research paper thumbnail of Comparative Analysis of Hydrodynamics Behavior of Microalgae Suspension Flow in Circular, Square and Hexagonal Shape Photo Bioreactors

American Journal of Computational Mathematics, 2016

Microalgae based biofuel is an emerging natural source of energy alternative to the fossil fuel. ... more Microalgae based biofuel is an emerging natural source of energy alternative to the fossil fuel. As microalgae are photosynthetic microorganisms, light is one of the limiting factors for its culture. Though many researches have been carried out for findings behind suitable culture system for the proper growth of microalgae, those are confined only to tubular Photo-bioreactor (PBR). This paper aims to make comparison among the horizontal loop photo bioreactors with different cross sections based on the analysis of hydrodynamics behavior. Three different geometrical shapes having vertical cross sections of circular, square and hexagonal PBR, have been proposed taking into account light intensity for microalgae culture. In this study, we simulate the flow dynamics of three types of PBRs and discuss the velocity, pressure and shear stress properties as microalgae endurance capacity depends on them. For the dimension of the three PBRs we considered here, each of them have radius of about 0.05 m while the length together with bending portion is approximately 20.5 m for a single loop. From the study, the hydrodynamic behaviors are observed to be quite dissimilar in case of three PBR's. In the straight portion the velocity profile is quite parabolic in tubular but distorted minimally in case of square and hexagonal PBRs. In the middle of the U-loop, a haphazard fluid distribution is noticed. The velocity magnitude and agitation of microalgae cells are higher in hexagonal than in square and tubular. The shear rate is less in case of tubular compared to square and hexagonal. A linear pressure drop is found from the inlet to the outlet for three PBR's. From this comparison, it can be said that the tubular one would be the best option for microalgae culture in case of industrial purposes.

Research paper thumbnail of Numerical Simulation of Two-phase Laminar Flow for CO 2 and Microalgae Suspension in the HLTP

This paper proposes a mathematical model of two-phase flow for carbon-dioxide and microalgae susp... more This paper proposes a mathematical model of two-phase flow for carbon-dioxide and microalgae suspension in an Horizontal Loop Tubular Photo-bioreactor (HLTP) taking into account the light irradiance. The model
with no-slip condition on the wall and zero outward normal stress at the outlet of the HLTP is used to simulate
the fluid phenomena inside the HLTP. The viscosity of the algal suspension is considered as a function of relative
viscosity related to concentration and growth rate of the microalgae. The simulation is carried out on the seventh
day of the culture. The effect of average irradiance in a day on the viscosity is investigated. The results show that
the two-phase flow model can capture the real behavior of the microalgae culture in the HLTP.

Research paper thumbnail of The Enhancement of Heat Transfer in a Circular Tube with Insert and without Insert by Using the Finite Element Method

Procedia Engineering, 2015

Research paper thumbnail of INTERNATIONAL JOURNAL OF MATHEMATICS AND COMPUTERS IN SIMULATION Comparison of Single-phase and Two-phase Flow Dynamics in the HLTP for Microalgae Culture

This paper aims to show dynamic behavior of microalgae suspension in a Horizontal Loop Tubular Ph... more This paper aims to show dynamic behavior of microalgae suspension in a Horizontal Loop Tubular Photobioreactor (HLTP). Two models of a single-phase flow and a two-phase flow have been proposed taking into account the light irradiance. The governing equations describing a single-phase flow are the continuity equation and the Navier-Stokes equation. The viscosity of the microalgae suspension is a function of microalgae cell concentration which varies in time. Using the governing equations of a single-phase flow together with the Cahn-Hiliard mass conservation equation, we can describe the dynamic behavior of a two-phase flow. The results obtained from both models are compared. It is noted that both results are significantly different. In the two-phase flow model, the mass transfer rate and the shear rate are higher than those obtained from the single-phase model.