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Research Article
Performance and Emissions of a Dual-Fuel Diesel-LPG Engine Operating at Low and Medium Loads
Issue:
Volume 15, Issue 4, August 2026
Pages:
92-101
Received:
19 June 2026
Accepted:
19 July 2026
Published:
24 July 2026
Abstract: Rural areas in Burkina Faso suffer from very limited access to electricity. In 2024, the rural electrification rate was estimated at 10.2%, compared to 87.8% in urban areas, for an overall national rate of 34.2%. Electricity generation using stationary diesel engines is a viable solution to address this disparity. Decentralized power generation facilities continue to face operating costs associated with diesel fuel and environmental concerns. In this context, the use of gaseous fuels such as Liquefied Petroleum Gas (LPG) or synthesis gas as the primary fuel in dual-fuel diesel engines could significantly mitigate this limitation. The objective of this study is to evaluate the overall performance and emissions of a Lister Petter diesel engine operating in dual-fuel mode at low and medium loads. The engine operated on diesel-LPG at a constant speed of 1,500 rpm under partial load. Specific fuel consumption in dual-fuel mode increased by 0.04 kg/kWh at low load compared to that of pure diesel, resulting in a maximum decrease in overall efficiency of approximately 2%. The two engine operating modes have comparable CO2 emissions. However, the diesel-LPG mode emits more CO and reduces NOx concentrations in the exhaust gases by an additional 25%. A maximum decrease of 60°C in the temperature of the exhaust gases was observed at medium load.
Abstract: Rural areas in Burkina Faso suffer from very limited access to electricity. In 2024, the rural electrification rate was estimated at 10.2%, compared to 87.8% in urban areas, for an overall national rate of 34.2%. Electricity generation using stationary diesel engines is a viable solution to address this disparity. Decentralized power generation fac...
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Research Article
Mathematical Modeling of Intensified Heat Transfer in Channels with Diaphragms During the Flow of Transformer Oils in Laminar and Transition Regions
Lobanov Igor Evgenievich*
Issue:
Volume 15, Issue 4, August 2026
Pages:
102-114
Received:
6 February 2026
Accepted:
28 February 2026
Published:
24 July 2026
Abstract: Mathematical mοdeling οf heat transfer in pipes with turbulatοrs at Reynοlds numbers characteristic οf the transient flοw regime is carried οut. The sοlutiοn οf the heat transfer prοblem fοr semicircular crοss-sectiοn flοw turbulatοrs based οn multiblock computing technοlοgies based on the solution of the Reynolds equations (closed using the Menter shear stress transfer model) and the energy equation (on multiscale intersecting structured grids) by the factorized finite volume method (FCOM) was considered. This method was previously successfully applied and verified by experiment for higher Reynolds numbers. 5. Implemented by the FKOM method, the study generated both local and integral, both stationary and unsteady characteristics of flow and heat transfer in a pipe with internal ribs for transitional and laminar coolant flow modes, which made it possible to determine the levels for these modes intensification of heat transfer, which correlate satisfactorily with the available experimental data. In the study, calculated results of enhanced heat transfer in pipes with diaphragms for the transient flow regime of trans-former oil were obtained using an analytical method - based on a 4-layer turbulent boundary layer scheme - which are in very good agreement with the numerical ones, which determines their mutual verification. The obtained patterns can be used in engineering and scientific calculations of intensified laminar and transition heat transfer during flow in channels with protrusions used in advanced heat exchangers, used, for example, in aviation, rocket, and space technology.
Abstract: Mathematical mοdeling οf heat transfer in pipes with turbulatοrs at Reynοlds numbers characteristic οf the transient flοw regime is carried οut. The sοlutiοn οf the heat transfer prοblem fοr semicircular crοss-sectiοn flοw turbulatοrs based οn multiblock computing technοlοgies based on the solution of the Reynolds equations (closed using the Menter...
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Research Article
Explicit Expressions for Calculating the Turbulent Friction Coefficient: A Review
Nkontchou Ngongang François,
Tchawe Tchawe Moukam*,
Tientcheu Nsiewe Maxwell,
Djiako Thomas,
Kenmeugne Bienvenu
Issue:
Volume 15, Issue 4, August 2026
Pages:
115-123
Received:
30 May 2026
Accepted:
22 June 2026
Published:
28 July 2026
DOI:
10.11648/j.ijepe.20261504.13
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Abstract: Research on friction in pipes remains complex. This complexity is due to the numerous parameters that must be considered when calculating the coefficient of friction f. Due to this complexity, many researchers have proposed multiple formulas for determining the friction coefficient. Today, there are a large number of explicit expressions for calculating the friction coefficient for each flow regime, whether for smooth or rough pipes. In this review, we set out to study the evolution of work on the friction coefficient and to present it. For this purpose, a large number of reviews have been used. Once this has been done, we identified more than 120 expressions, most of which were explicit. We have thus noted that many of these expressions are approximations of the implicit Colebrook-White equation. Similarly, a good number are derived either from direct developments using computer tools, or from mathematical methods that are sometimes very long. However, in general, we have found that all these expressions only take into account the three parameters present in the Colebrook-White formula. These parameters are: Reynolds number Re, the absolute roughness ɛ and the diameter D. We would like to point out that these parameters were deemed insufficient to minimise the difference between the calculated values and the values observed on site with regard to the friction coefficient.
Abstract: Research on friction in pipes remains complex. This complexity is due to the numerous parameters that must be considered when calculating the coefficient of friction f. Due to this complexity, many researchers have proposed multiple formulas for determining the friction coefficient. Today, there are a large number of explicit expressions for calcul...
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