Volume 12, Number 1, June 2024 http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/832 2026-04-26T00:20:35Z 2026-04-26T00:20:35Z Grandhi, Raj Kiran Roy, Arnab http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/869 2025-05-07T08:36:58Z 2024-06-01T00:00:00Z

Detached Eddy Simulations of a Reaction Control Jet from an Axi-Symmetric Body in a Supersonic Crossflow Grandhi, Raj Kiran; Roy, Arnab The introduction of a control jet into a supersonic cross flow yields a substantial region of separated flow, manifesting in the vicinity of the injection site. This, in turn, alters the distribution of pressure on the primary body, thereby influencing the effectiveness of the injected jet’s capacity to produce the desired control forces and moments. In the context of an axi-symmetric parent body, this disruption typically leads to a reduction in effectiveness, owing to the overflow of the shock structures encompassing the parent body. The present study investigates the injection of a reaction control jet into a supersonic crossflow using different Detached Eddy Simulation (DES) techniques. The side jet is injected from an orifice on an axi-symmetric parent body, which is aligned with the crossflow direction. The effects of the side jet on the flow field are analysed in terms of general flow features and spectral behaviour of pressure and turbulent kinetic energy. The DES results are compared with those obtained from RANS using various turbulence models. The overall effect of a transient interaction pulse is characterized using URANS and two different DES models.

2024-06-01T00:00:00Z George, Judith O. Oloruntobi, Olalere Butt, Stephen D. http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/868 2025-05-07T08:34:29Z 2024-06-01T00:00:00Z

Development of a Probabilistic Correlation between the Gamma Ray Index and Shale Volume Factor to Improve Resource Estimation for the Niger Delta Basin, Nigeria George, Judith O.; Oloruntobi, Olalere; Butt, Stephen D. The shale volume factor is among the critical petrophysical parameters for reservoir characterization and formation evaluation. Inaccurate estimates of the shale volume factor can lead to poor reserves or resource estimates and wrong business decisions. While the current industry standard is to estimate the shale volume factor from the gamma ray logs using the concept of the gamma ray index, a relationship between the shale volume factor and the gamma-ray index needs to be established for any region/basin under consideration. For most applications in the Niger Delta Basin, a linear relationship is often assumed. However, there is no proven relationship between the shale volume factor and the gamma-ray index for the formations in the Niger Delta Basin. This paper proposes a new shale volume factor prediction correlation for the Niger Delta Basin in Nigeria. The correlation development is based on establishing a relationship between the shale volume factor obtained from cores and the gamma ray index obtained from petrophysical logs for over thirty wells drilled across the Niger Delta Basin. The results show that the relationship between the shale volume factor and the gamma-ray index is not linear as often assumed but a power law model. The new probabilistic correlation predicts lower shale volume factors than the linear model for all ranges of the gamma-ray index. This recent correlation will significantly impact how the hydrocarbon resources and reserves are quantified in the Niger Delta Basin.

2024-06-01T00:00:00Z Tasmiha, Samiha Wahid, S. M. Taseen Sabid, Zayed Al Afif, Ahmed http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/867 2025-05-07T08:31:25Z 2024-06-01T00:00:00Z

Fabrication of Solar-Powered Pumped-Storage Hydroelectric Power Station Tasmiha, Samiha; Wahid, S. M. Taseen; Sabid, Zayed Al; Afif, Ahmed Renewable energy is now accepted as the preferred alternative for electricity generation and as the replacement for fossil fuels. Worldwide demand for energy derived from renewable resources, especially hydro energy, is rising in tandem with rising fuel prices and environmental concerns. Our power station aims to harness the renewable energy potential of solar and hydroelectric power, combining them in an innovative and efficient manner. The prototype power station incorporates two main components: solar photovoltaic (PV) arrays and a pumped storage hydroelectric system. The solar PV arrays consist of a network of solar panels that capture sunlight and convert it into electricity. The generated solar power is used for both immediate consumption and for pumping water to a higher elevation. Efficiency and efficacy differ substantially between the values obtained from upstream and downstream. Significantly surpassing downstream, upstream generates 30W of electricity at 20V of voltage and 1.5A of current. By comparison, downstream has to work with a voltage of 42mV, a current of 0.04A, and a power production of just 0.00168W. These differences amply show that the upstream arrangement makes better use of solar energy. As such, upstream proves to be the superior choice for using solar energy because of its increased productivity and performance.

2024-06-01T00:00:00Z Huq, Md. Habibul Rahman, Md. Mafizur Hasan, G. M. Jahid http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/866 2025-05-07T08:27:58Z 2024-12-01T00:00:00Z

Temporal land-use change of a reclaimed land in greater Dhaka and its impact on natural water cycle Huq, Md. Habibul; Rahman, Md. Mafizur; Hasan, G. M. Jahid This study aims to explore the land-use induced impact on runoff and recharge of an impending urban growth on reclaimed land filled with sands in greater Dhaka to concede the low impact development through practicable methods. Having analyzed the temporal land-use change by Curve Number (CN), GISbased Soil Conservation Service - Curve Number (SCS-CN) method has been used to evaluate the runoff of the study area. Initial land-use in 2010 with a higher CN 86 resulted in a lower CN 72 in 2020-2022 due to land-use change (pre-developed/existing condition) with permeable soil for urban development. However, the gradual land-use change resulted in more imperviousness and an increasing trend in CN. With ultimate CN 84, approximately 243% more runoff was predicted during complete urbanization in 2040 and beyond as opposed to CN 72 in 2020-2022. Due to the existing higher groundwater table of the area, the Water Table Fluctuation (WTF) method has been used to find the natural recharge potential. As higher CN results in more runoff and recharge loss, ultimate natural recharge potential with CN 84 declines to more than 50% of the pre-developed condition. Results from the methods suggested a comprehensive hydrological forecasting due to land-use change on reclaimed land land with assorted options for natural water cycle balance.

2024-12-01T00:00:00Z