International Journal of Engineering and Applied Physics

Experimental and FEM Vibration Analysis of Impellers used for Water Pump

Haider Jasim — Wed, 24 May 2023 00:00:00 -0400

The impeller is an essential component of the water pump. Vibrations of the impeller have a significant effect on the pump's performance, as well as posing some damaging effects. In this study, the vibration of three different types of impellers for water pumps (brass, bronze, and plastic) was evaluated experimentally and compared with computational finite element method (FEM). A number of variables includes temperature, flow rate, impeller material composition, and the chemical composition of water been studied. The findings indicated that vibration issues increased as flow rate increased. The plastic impeller has the highest vibration rate compared to brass and bronze impellers under the identical testing conditions. The vibration rate of impellers tested in seawater is higher than that them tested in tap water. Increasing the temperature of the water accelerates the vibration process. Cavitation occurs in seawater at a lesser Net Positive Suction Head (NPSH) than in tap water.

An Efficient Logarithmic Ratio Type Estimator of Finite Population Mean under Simple Random Sampling

Awwal Adejumobi, Mojeed Abiodun Yunusa, Yahqub A. Erinola, Kabiru Abubakar — Wed, 24 May 2023 00:00:00 -0400

The use of auxiliary information has become indispensable for improving the exact of estimators of population parameters like the mean and variance of the variable under study. A great variety of the techniques such as the ratio, product, and regression methods of estimation are commonly known in this esteem. In this paper, we propose an efficient logarithmic ratio type estimator for finite population mean estimation under simple random sampling. The expression for the bias and mean squared error (MSE) of the proposed estimator is obtained up to the first order of approximation. The conditions under which the proposed estimator is more efficient than the existing ones are established. An empirical study using three data sets is also conducted to validate the theoretical findings and the results revealed that the suggested estimator is better than the existing estimators considered in the study.

The parameter update of Lithium-ion battery by the RSL algorithm for the SOC estimation under extended kalman filter (EKF-RLS)

elmehdi Nasri, Tarik Jarou, Jawad Abdouni, Salma Benchikh, Sofia Elidrissi — Wed, 24 May 2023 00:00:00 -0400

The lithium-ion battery is the key power source of an electric vehicle. The cornerstone of safe transportation vehicles is reliable real-time state of charge (SOC) information. Since batteries are the primary form of energy storage in electric vehicles (EVs) and the smart grid, estimation of the state of charge is a critical need for batteries. The SOC estimate approach is considered to be precise and simple to apply for such applications. In this paper, After studying a battery model with an appropriate resistor-capacitor (RC) circuit, A lookup table derived from experimental studies describes the nonlinear connection between the Open Circuit Voltage Voc and the the state of charge. However, if temperature or SOC varies, the equivalent circuit model's characteristics will vary, decreasing the accuracy of SOC calculation. The recursive least squares (RLS) and nonlinear Extended Kalman filters are used in this research to offer a charge estimate technique with online parameter identification to handle this problem. RLS dynamically updates the Thevenin model's parameters. In order to improve the precision of SOC prediction under charge and discharge settings, we presented a regression least-squares-extended Kalman filter (RLS-EKF) estimation approach in this study. The objective of this research is to ensure the updating of the battery parameters and to evaluate the influence of this improvement on the convergence of the state of charge towards the real value. The simulation results suggest that the RLS EKF estimation technique, which is based on precise modeling, may greatly increase SOC estimation accuracy.

Behavior of Masonry Walls with Respect to Seismic Stress, Analysis and Recommendation

RACHID ZAIN, SERROUKH Mostafa — Wed, 24 May 2023 00:00:00 -0400

Structures with masonry infill panels and reinforced concrete frame are widely used structural systems and by lack of knowledge considered secondary, masonry infill walls are considered until now as non-load-bearing elements, therefore the role of taking and transmitting vertical and horizontal loads (seismic) is ensured only by the reinforced concrete structure. However, experience from past earthquakes around the world has shown that this calculation approach is simplifying and approximate, because we have found during the analysis of earthquake damage that the neglect of masonry walls in calculations can decisively influence and even upset the response of structures to seismic forces. The tests carried out in our research and the numerical modelling carried out on several cases have shown that the effect of shear stress on gantry masonry structures can be taken into account by replacing in the numerical modelling the masonry with equivalent diagonals whose thickness will be calculated according to the physical and mechanical characteristics of the gantry and the masonry.

Pentagon Patch Antenna for WLAN at 2.6 GHz

Wed, 24 May 2023 00:00:00 -0400

In this paper an antenna with a pentagonal patch design is being prototype on FR-4 epoxy material fed by a microstrip line with a hexagonal parasitic element for bandwidth enhancement. A pentagon microstrip antenna with hexagonal parasitic elements is designed and analyzed its properties for WLAN application at 2.52 GHz. The pentagon microstrip antenna with hexagonal parasitic element is being analyzed in terms of return loss, gain in dB and VSWR, etc. The experimental result shows a patch antenna is operating frequency at 2.52 GHz, with the return loss parameter is observed as -9.84 dB, and the VSWR ratio is < 2 respectively.

Application of the EEMD Algorithm for the Monitoring of the Cutting Tool wear

claude mukaz — Wed, 24 May 2023 00:00:00 -0400

In this work, it is a question of a monitoring of cutting tool wear in mechanical turning. This monitoring is carried out in three phases which correspond to the life of the tool. To achieve this objective of improving the monitoring of the cutting tool, we have proposed the EEMD processing algorithm which decomposes a large signal into small signals (IMFs) by comparing it to the EMD algorithm, which is an algorithm used in the analysis of non-linear and non-stationary signals. The phenomenon of mode mixing is one of the major drawbacks of EMD. The EEMD eliminates the mode mixing effect. The EEMD principle is to add extra white noise to the signal with a certain number of tries.

Evaluation Of Omotosho Gas Power Station Based on Best Industrial Practice

Wed, 24 May 2023 00:00:00 -0400

This study is solemnly concerned with the performance evaluation of the Omotosho gas Power plant over a period of four years. The station is made up of 8 units of 42MW Gas Turbine (GT) each. Data of necessary parameters such as average actual load, the install capacity of the station, hours of operation, energy generated, peak load, amount of gas consumed, the Net calorific value of gas, generator efficiency and available turbine unit was obtained and computed to measure the performance of the station between year 2014 to 2017. The results indicated that the average availability of the station varies from 45.02% to 89.18% which is against the recommended industrial practice of 95%. Also, the reliability of the station varies from 57.95% to 86.62% which is against the recommended 99.9% for best industrial practice. Likewise, the capacitor factor of the station varies from 16.29% to 49.98%, only the CF of 2016 which is 49.98% conform to the best industrial practice of 40-80% for the TP plant. Furthermore, the thermal efficiency of the station varies from 26.66% to 30.03% and the total efficiency varies from 26.66% to 29.43% which is against the recommended standard of 49% for thermal efficiency and 80% for overall efficiency. The findings revealed that the station performance is below the recommended standard, also this study gives an indices to evaluate gas power station in accordance with industrial practice. The findings of this research can be used to evaluate the performance of any gas station. This study, therefore, suggests that maintenance crew should maintain Omotosho power plant unit in accordance with the manufacturer’s specifications in order to increase the reliability of the station.

ANSYS-CFX Simulation and Experimental Studies on Centrifugal Pump Impeller Design: Performance Effects Using Corrosive and Non-corrosive Resources

Wed, 24 May 2023 00:00:00 -0400

Corrosive fluids, namely saline water, hydrochloric acid and methanol and non-corrosive fluids, namely, water, gasoline and kerosene can be tested for efficiency and reliability on an existing H47 centrifugal pump impeller’s performance. To analyze the pump performance, ANSYS student version 2022 software was used – wherein; head rise (H), pump speed (N), discharge rate (Q) and inlet pressure of 20-120m, 2000rpm, 144m³/h and 0 atm were respectively specified as initial and boundary conditions in the computational fluid dynamics (CFD) tool. CFD for inlet and exit blade angles of 35^o, 38^o, 41^o and 47^o, 50^o, 53^o were respectively simulated for all fluid type using a 7-bladed impeller to obtain contour plots and pressure and velocity distribution results of the analysis. It was deduced that the overall efficiency of the centrifugal pump depends on the outlet blade angle and fluid type, while the power used rises with both inlet and outlet blade angles. Further studies should be channeled towards analyzing the variations in N, Q, H, impeller blade number (Z) and its width, for this particular type of impeller.

Application of the EEMD and CEEMDAN algorithm for non- linear signal processing

claude mukaz, Moise NGOYI KASANJI — Wed, 24 May 2023 00:00:00 -0400

Nonlinear signals are often encountered in many applications, such as biomedical signal processing, fault diagnosis, and image processing. Ensemble empirical mode decomposition (EEMD) and complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) algorithms have been proposed for the analysis of nonlinear and non-stationary signals. In this paper, we compare the performance of EEMD and CEEMDAN algorithms based on the Root Mean Square (RMS) statistical indicator for nonlinear signal processing. We evaluate the effectiveness of these algorithms using two synthetic signals and a real-world vibration signal from a gearbox. The results show that CEEMDAN provides a 50% improvement over EEMD in terms of RMS and the number of trials or computation time required. The study also shows that EEMD is prone to mode mixing and requires a large number of trials to achieve accurate results. On the other hand, CEEMDAN overcomes the mode mixing issue and provides more accurate results with fewer trials or computation time. Our findings suggest that CEEMDAN is a more efficient algorithm for nonlinear signal processing, particularly in real-world applications where computation time is a limiting factor.

Dynamic Force Analysis on Blades of Centrifugal Pumps using Computational Fluids Dynamics Simulations

Victor Antwi — Wed, 24 May 2023 00:00:00 -0400

Mechanical stress on the blade of a centrifugal pump is a crucial factor in the design and operation of hydraulic pumps. Therefore, in this study, the tangential force on the blade of a centrifugal pump at different flow rates and directions was investigated using Computational Fluid Dynamics (CFD) simulations. The CFD simulations were performed based on the k-? turbulence model and were validated through experimental measurements. The study revealed that the tangential force is dependent on the flow rate of the fluid being pumped, and understanding how it changes with varying flow rates is essential for optimizing the performance of the pump and preventing potential fractures. On the other hand, the absolute pressure on the blade was also investigated. The absolute pressure distributions on the blade pressure side, suction side, leading edge, and trailing edge were analyzed for different flow rates. The highest pressure distribution is found on the pressure side than the suction side. On the blade pressure side, a relatively large pressure is found near the trailing edge. Overall, the study provides insights into the complex relationship between flow rate and tangential force in centrifugal pumps and highlights the importance of understanding this relationship for successful pump design and operation.

Optical characterisation of polarised light beam under different aqueous concentrations

Desmond Appiah, Victor Antwi, Michael Gyan, Kwesi , Fortune Addo-Wuver — Wed, 24 May 2023 00:00:00 -0400

In this study, the optical activity of salt, brown and white sugar solutions of different concentrations is determined. The optical rotation angle as a function of wavelength was studied using different optical color filters. Sodium-D light and laser source of light were used. The optical activity was found to depend on the type of sugar, sugar concentration and the wavelength of the light used. The study revealed that the optical activity was linearly dependent on the concentration of the sugar solution (both white and brown). Cyan light recorded the highest angle of rotation while red light recorded the lowest. It also found that brown sugar has a greater ability to rotate polarized light than white sugar due to the presence of potassium and magnesium components. It is worth noting that the salt solution is optically inactive because it lacks microscopic mirror symmetry. Finally, the findings provide an understanding of the characteristics of polarized light under different solution concentrations and can serve as a guide for conducting further research on high-efficiency polarizers.