Journal of Research and Applications in Mechanical Engineering

Heat Transfer of MHD Non-Newtonian Fluid in Presence of Thermally Stratified Medium

C. Sulochana — 2024-10-25

In this paper, investigated on heat transfer of MHD non-newtonian fluid in presence of thermally stratified medium. The momentum and energy equations associated with the partial differential equations are transformed into highly nonlinear ordinary differential equations by using similarity transformations. Kummer's function is used to represent the analytical solutions to these equations, and obtained the numerical solution of energy equation using analytical solution of flow. Numerical analysis carried out through BVP5C and ND Solver commands, and comparing with analytical method while using wolfram language mathematica and values are accurate. Graphically represented all physical parameters and also represented in Table form and Bar & Contour Graphs. In presence of thermal stratification, it is seen that the rate of surface heat transfer decreases whenever rising in viscoelastic and magnetic parameter, Prandtl number. Temperature distribution exhibits the reverse effect. Applications are geothermal & power plant condensation systems, geological transport, lake thermohydraulics, volcanic flows.

Estimation of the Fatigue Life of Test Specimens Made from Ferrous Metals Using Graphical Technique

K. Srisathit — 2024-10-25

New engineers in mechanical design occasionally encounter difficulty when forecasting the fatigue life of created parts under dynamic conditions. This is because, during the design phase, the size of the pieces is regularly adjusted along with the changing material type, the modified design factor, and even the magnitude of the load in order to generate a prototype that is most compatible with the design circumstances. However, theoretically estimating a part's fatigue life is challenging and time-consuming. Therefore, It might not be the ideal option for the current mechanical design process because it contradicts the QCD paradigm, which is thought to be the cornerstone of industrial production. As a result, this article presents a graphical technique using AutoCAD software to estimate the fatigue life of test specimens made of ferrous metals with ultimate tensile strengths ranging from 490 to 1400 MPa. This approach produces accurate and reliable results when compared to an equation-based fatigue life estimation procedure. This method shortens the time and expense of design. Additionally, as compared to the conventional way, increases the mechanical design's flexibility and agility.

Design Procedure of an Axial Flow Irrigation Pump

Kittipass Wasinarom — 2024-11-05

The paper presents the design procedure of an axial flow irrigation pump. It was designed to deliver a flow rate of 9,000 L/min with a head of 4 m at the Best Efficiency Performance point (BEP). The target hydraulic efficiency was 75%. It started with the preliminary design which predefined the inlet and outlet blade angle of the impeller and the stator vane using a triangular velocity diagram. After that, the other components in the pump system which are the inlet bell, duct, and trailing cone were constructed in the Computer Aided-Design (CAD) software. Then, the flow structure of the pump system was obtained using Computational Fluid Dynamics (CFD). The impeller blade channel, guide vane profile, and the flow channel throughout the pump system were improved to attain target efficiency. This was done by awareness of the development of high velocity (jet flow) and low velocity wake (wake flow) along the entire flow channel. The blade profile was adjusted to minimize wake region while the high jet velocity was reduced. By continuously improving the blade profile, the final version’s hydraulic efficiency was 75.27%. The head was 5.68 m with the flow rate of 11,676 L/min.

Experimental Investigation of the Effects of a Reduced Exhaust Gas Re-circulation Rate on the Performance and Emissions of CI Engines Running on Biodiesel made from Dairy Waste Scum Oil

S.B. Anjappa — 2024-11-05

Biodiesel resembles the qualities of fossil diesel while it is also proven to be a greener fuel and viable alternative. However, the primary challenge of using biodiesel was higher emissions of Nitrogen oxides (NOx). Hence to minimize the NOx, an exhaust gas re-circulation (EGR) system could be utilized and could resolve the challenges associated with this higher NOx emissions. In this study, dairy waste scum oil biodiesel was prepared and blended with diesel at 20% by volume (B20) and three different EGR percentages 5%, 10%, and 15%, were investigated on the characteristics of CI engine. Based on the test outcomes, a drop in NOx has been observed with a 15% rate of EGR which is 6.1% lower than conventional diesel. Moreover, brake thermal efficiency increased by 11% as compared to diesel. However, a slight increase in other exhaust emissions was noticed with EGR. The findings indicate that utilizing a lower rate of exhaust gas re-circulation (EGR) at 15 % in conjunction with a B20 blend of dairy waste scum oil biodiesel yields optimal engine performance while minimizing NOx emissions.