Computational analysis on film cooling effectiveness over a flat plate using different coolant injection hole geometries are reported. The designed computational setup and flow physics are suitably validated against the existing experimental results for an injection angle of 30°. The present study reports and compares the degree of film cooling effectiveness obtained by the different orientations of the coolant injection holes and their geometry, hole arrangements in the rows and number of rows. The computational domain was designed using Ansys Fluent. The blowing ratio is systematically ranged between 0.67 and 1.67. The performance of a given film cooling scheme is reported in terms of centreline (ηcl) and spatially averaged (η_sa) adiabatic effectiveness. It is observed that for single hole configuration, the semi-elliptic geometry increases the ηcl by ~66.67% up to x/D(ratio of downstream distance from hole to diameter of hole) = 50 at lower blowing ratios (0.67 and 1.00) and by ~50% up to x/D=100 at higher blowing ratios (1.33 and 1.67). For ηsa, an increment of ~200% and ~60% is achieved for all blowing ratios using the triangular and semi-elliptic geometries, respectively. For the multiple row arrangements, the two staggered rows delivered an increment in ηcl of ~77% up to x/D=50 and ~54% up to x/D=100. The two staggered configurations at 0° gave the highest effectiveness increment of ~177% up to x/D=50 while it was ~100% for up to x/D=100. Results indicate that the triangular geometry shows the highest values of the film cooling effectiveness, and a semi- elliptic geometry utilizes ~50% of the coolant mass flow than other coolant injection hole geometries while delivering higher effectiveness values.

Polymer-based composites have been drawing the attention of the research community for many decades, not only in academia but also in industry. However, continuously increasing environmental concerns have led the researchers to focus on natural composite materials. This is a challenge for researchers to develop a natural composite without compromising the composites’ excellent mechanical properties and tribological performance. In this research, coir and sugarcane are selected as the natural fillers, and epoxy resin has been chosen for matrix material. To look into the crystallinity of composites, XRD analysis was done. In addition, a mechanical study was done to look at the manufactured composites’ tensile and flexural characteristics. The tribological performance (i.e., wear rate and friction coefficient) of the composite samples is investigated by using a pin-on-disc setup. The parameters such as filler loading and normal load affecting the tribological performance of epoxy-based natural composites are studied. The results show that the wear and friction characteristics of the composite reinforced with sugarcane and coir were 10.78% and 57.80% lower than those of the neat composite, respectively.