Engineering and Technology Journal

Research Paper

Computational Single and Multiphase Approaches to Investigate the Hydrothermal Behavior of Hybrid Nano-fluid in Plain and Wavy Tubes

Ahmed S. Habeeb; Sattar Aljabair; AbdulHassan A. Karamallah

Volume 41, Issue 7 , July 2023, Page 1-19

https://doi.org/10.30684/etj.2023.136449.1316

Abstract

The newest class of heat transfer improvement is accomplished by using hybrid Nano-fluids. Therefore, the heat transfer and pressure drop of a mixture of Iron oxide (Fe3O4) and Magnesium ... Read More ...

Research Paper

Experimental and Numerical Study of Spur Gears With Lightening Holes

Almurtadha A. Ahmed; Ali R. Hassan

Volume 41, Issue 7 , July 2023, Page 1-11

https://doi.org/10.30684/etj.2023.134713.1246

Abstract

The gear is a very important component of power transmission in a flying vehicle and rotating mechanisms etc... In this paper, the dynamic effect and stresses generated as a result ... Read More ...

Research Paper

Investigation of Frequency-Domain-Based Vibration Signal Analysis for UAV Unbalance Fault Classification

Luttfi A. Al-Haddad; Alaa A. Jaber; Paramin Neranon; Sinan A. Al-Haddad

Volume 41, Issue 7 , July 2023, Page 1-9

https://doi.org/10.30684/etj.2023.137412.1348

Abstract

The flying reliability of Unmanned Aerial Vehicles (UAVs) and flying robots, which directly determines the operational degree of safety, is becoming more important in recent intelligent ... Read More ...

Research Paper

Effect of ECAP process on mechanical properties and microstructure of AA-6061 recycled chips

Rawa H. Mohammed; Ayad F. Shahab; Alireza F. Rezaei

Volume 41, Issue 7 , July 2023, Page 1-16

https://doi.org/10.30684/etj.2023.137807.1367

Abstract

The oxidation of aluminum machined chips makes successful recycling via the traditional re-melting technique difficult. A viable solution to this problem is to utilize solid-state recycling ... Read More ...

Research Paper

Mathematical Model of Properties and Experimental Fatigue Investigation at Elevated Temperatures of Functionally Gradient Materials

Ziadoon M.R Al-hadrayi; Ahmed N. Al-Khazraji; Ahmed A. Shandookh

Volume 41, Issue 7 , July 2023, Page 1-14

https://doi.org/10.30684/etj.2023.137509.1352

Abstract

Fatigue that occurs at elevated temperatures is called thermal fatigue. High temperatures and cycling loads cause thermal fatigue that can cause component failures. In this paper, induced ... Read More ... Fatigue that occurs at elevated temperatures is called thermal fatigue. High temperatures and cycling loads cause thermal fatigue that can cause component failures. In this paper, induced the mathematical models for functionally gradient materials and three models of functionally gradient materials (FGMs) manufactured by permanent casting were tested to predict their thermal fatigue life. FGMs have been tested to determine the effect of fatigue and temperature interactions. FGMs models were of FGM1, FGM2, and FGM3 respectively, with the following volume fractions and gradations: [100%Al-50%Al50%Zn-50%Zn50%Al-100%Zn], [100%Al-30%Zn70%Al-70%Zn30%Al-100%Zn] and [100%Al-70%Zn30%Al-30%Zn70%Al-100%Zn]. The experimental procedure presented the mechanical properties as modulus of elasticity at two levels of temperatures (80 oC, and 160 oC). Through the results of the tensile test at high temperatures, it was noted that the reduction percentage was high in the second type. This was especially for the yield strength value, where the percentage reached 43% at 160 °C. In the second type, the ultimate strength was affected more at 160 °C: the decrease percentage reached 33%, and the elastic modulus at the same temperature fell by 32%. The third type is the least affected at high temperatures, as the percentage of properties decrease at 160 °C reached 16, 17, and 16% for modulus of elasticity, ultimate strength, and yield strength, respectively. Fatigue strength is the most significant among the mechanical properties, where the highest value of the fatigue limit for the third type was experimentally 149.68 MPa. While the lowest value of fatigue strength was the second type, and at the same time, on the contrary, it was less affected at high temperatures, with a rate of 8%, which reached the decrease. The simulation results from the ANSYS program regarding fatigue at high temperatures were acceptable and gave reasonable variation ratios and were very close to the experimental results.

Research Paper

The Effect of Electrode Geometry and Pre-heating Treatment on Resistance Spot Welding Strength

Lana I. Hassan; Hameed D. Lafta

Volume 41, Issue 7 , July 2023, Page 1-9

https://doi.org/10.30684/etj.2023.138070.1371

Abstract

Resistance spot welding (RSW) is one of the most significant and common metal joining methods used in industries. The present paper discusses the comparative performance of resistance ... Read More ...

Research Paper

The Effect of Vibrating Inner Cylinder on Natural Convective Heat Transfer in Concentric and Eccentric Horizontal Cylindrical Annuli

Baydaa K. . Khudhair; Adel M. Saleh; Ali L. Ekaid

Volume 41, Issue 7 , July 2023, Page 1-16

https://doi.org/10.30684/etj.2023.137848.1362

Abstract

In this study, natural heat convection caused by centric and vertically eccentric long horizontal cylinders under the influence of vibration is experimentally investigated. The internal ... Read More ... In this study, natural heat convection caused by centric and vertically eccentric long horizontal cylinders under the influence of vibration is experimentally investigated. The internal wall of the annulus is heated and kept at a constant heat flux, while the outside wall is cooled and maintained at a constant temperature. The vibration frequency impacts the annular convection heat transfer process and the effects of the Rayleigh number, heat flow, and eccentricity. This work employed a moderate, laminar-ranging Rayleigh number from (5×104 to 6.48×106), while the eccentricity range is varied from (-0.667, 0, and+0.667). The investigation is carried out at five different frequencies (0, 2, 5, 10, 15, and 20 Hz); therefore, it was decided to compare the case under the same circumstances in both the absence and presence of vibration. The present results' verification worked exceptionally well in concordance with previous studies. When heat fluxes are considered, the study demonstrates that the temperature difference along the gap (radial difference) between the two cylinders significantly decreases for negative as opposed to positive eccentricities for each Rayleigh number. For different eccentricities, it was discovered that the temperature difference decreased as the Rayleigh number increased. Along with these reductions, the temperature difference was promoted as the vibration frequency increased, which is significant at (20 Hz) within the range considered for controlling parameters. It was also observed that the decrease in temperature difference is higher for the negative eccentric position than for the centric and positive positions. At vertical positive eccentricity at a low Rayleigh number, the gain in vibrational average Nusselt number caused by applying vibration had a minimum value of 22.50601475%, While at the higher value of the Rayleigh number, the maximum increase in negative vertical eccentricity was 86.66933125%. However, the gain in the average Nusselt number depends on the position of the heated inner cylinder, the Rayleigh number, and the vibrational frequency.

Volume & Issue: Volume 41, Issue 7, Mechanical Engineering, July 2023 (Mechanical Engineering)

Computational Single and Multiphase Approaches to Investigate the Hydrothermal Behavior of Hybrid Nano-fluid in Plain and Wavy Tubes

Abstract

Experimental and Numerical Study of Spur Gears With Lightening Holes

Abstract

Investigation of Frequency-Domain-Based Vibration Signal Analysis for UAV Unbalance Fault Classification

Abstract

Effect of ECAP process on mechanical properties and microstructure of AA-6061 recycled chips

Abstract

Mathematical Model of Properties and Experimental Fatigue Investigation at Elevated Temperatures of Functionally Gradient Materials

Abstract

The Effect of Electrode Geometry and Pre-heating Treatment on Resistance Spot Welding Strength

Abstract

The Effect of Vibrating Inner Cylinder on Natural Convective Heat Transfer in Concentric and Eccentric Horizontal Cylindrical Annuli

Abstract