Browsing by Author "Rahman, M.M.,"

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Numerical and analytical solutions of new Blasius equation for turbulent flow
(Elsevier Ltd, 2023) Rahman, M.M.,; Khan, S.,; Akbar, M.A.
The Blasius equation for laminar flow comes from the Prandtl boundary layer equations. In this article, we establish a new and generic Blasius equation for turbulent flow derived from the turbulent boundary layer equation that can be used for turbulent as well as laminar flow. The analytical and numerical solutions have been investigated under specific conditions to the developed new Blasius equation. The analytical and numerical results have been compared through tables and graphs to validate the established model. In fluid dynamics, analytical solutions to complicated systems are tedious and time-consuming. Changing one or more constraints can introduce new challenges. In this case, symbolic computation software provides an easier and more flexible solution for fluid dynamical systems, even if boundary conditions are adjusted to explain reality. Therefore, the MATLAB code is used to investigate the new third-order Blasius equation. The comparison and graphical representations demonstrate that the achieved results are encouraging.
PAPR Reduction in OFDM Signal by Incorporating Mu-Law Companding Approach into Enhanced PTS Scheme
(De Gruyter Open Ltd, 2020) Ibraheem, Z.T.,; Rahman, M.M.,; Fazea, Y.,; Ahmed, K.K.
Orthogonal Frequency Division Multiplexing (OFDM) is a potential transmission approach for high capacity communication systems. Despite the many advantages of OFDM, the major downside is the high peak-To-Average power ratio (PAPR) which increases the system complexity, reduces the efficiency of the system, causes degradation in BER performance, and makes OFDM sensitive to nonlinear distortion in the transmission. Various methods have been proposed to deal with the PAPR problem, including the partial transmit sequence (PTS) that has attracted considerable attention. Hence, this paper presents a hybrid approach combining an enhanced PTS technique with Mu-Law companding. The PTS technique was enhanced through improving its sub-block partitioning scheme, where the enhanced partitioning scheme consolidated a conventional interleaved partitioning into an adjacent partitioning scheme. This incorporation of Mu-Law characteristic in time domain for PAPR reduction in OFDM essentially enhances the PAPR reduction performance, based on using numerical simulation results. Consequently, though the pseudorandom sub-block partition method obtains better PAPR reduction more than the other sub-block partition schemes (interleaved and adjacent) of ordinary PTS, it is quite difficult to be designed. The findings show that the enhanced PTS technique with Mu-Law companding, while maintaining low computational complexity, performs significantly better than the pseudorandom partitioning PTS on various types of modulation formats and subcarriers.
Performance analysis of non-renewable energy in Bangladesh
(Institute of Advanced Engineering and Science, 2017-02) Rabbani, M.G.,; Sattary, C.T.,; Mamun, M.R.A.; Rahman, M.M.,; Khan, M.N.H.
The demand of energy is dramatically increased nowadays and the demand either can renewable or non renewable depends on the drawbacks. Hence, non renewable energies show the better performance where the limitations are comprisable very few and environmental friendly. Already developed countries are being used renewable energies as the main sources of energy to produce electricity where it proved the less easy and more benefits. However, non renewable energies such as natural gas, gas generator and so on still have been producing more and more electricity and this amount is around 10 times more than renewable energies especially developing countries like Bangladesh. This paper is being discussed the importance of renewable energies and non renewable energies to produce electricity, comparing the different countries electricity production and the using sources. Here analysis the data of different power plants in Bangladesh and the types of fuel, CO2 emission and electricity production. In additionally, Gazipur district has been selected to show the power consumption factories with the cost analysis in selected fuel types. © 2017 Institute of Advanced Engineering and Science. All rights reserved.