http://210.212.227.212:8080/xmlui/handle/123456789/456 2026-05-17T00:05:01Z 2026-05-17T00:05:01Z Vaishnav, S Shafi, K A http://210.212.227.212:8080/xmlui/handle/123456789/466 2023-10-07T07:13:57Z 2023-05-01T00:00:00Z

NUMERICAL INVESTIGATIONS ON SYNTHETIC JET IMPINGEMENT COOLING USING MULTIPLE ORIFICE Vaishnav, S; Shafi, K A A synthetic jet generally consists of a cavity with a driver attached on one side and an orifice on the opposite side. When the driver moves back and forth, the jet will generate an unsteady flow through the orifice and the flow will move downstream to a surface forming an impinging flow. When the jet is in the ejection cycle, the diaphragm will expel flow out from the orifice and form a vortex near the orifice. If the propulsion is large enough, the vortex will move downstream before the jet orifice flow reverses and starts to suck in flow. The computational process is carried out using the commercial software ANSYS Fluent. In this study, the heat transfer characteristics of synthetic jet impingement cooling with multiple orifice (2,4 and 16 orifices) are analyse with different operating frequencies (f=1Hz to f=5Hz and f=100Hz to f=500Hz) with different Reynolds number (Re=5000,10000 and 20000) well as Strouhal number (St=0.006 to St=0.030). The results demonstrate that high frequency synthetic jets show better heat removal capacity than lower frequency at the same Reynolds number. Also, the variation of area averaged Nusselt number depends on Strouhal number or dimensionless stroke length.

2023-05-01T00:00:00Z Rahul, Raj Shafi, K A http://210.212.227.212:8080/xmlui/handle/123456789/465 2023-10-07T07:08:04Z 2023-05-01T00:00:00Z

EFFECT OF CRYOGENIC TREATMENT ON THERMAL AND MECHANICAL PROPERTIES OF HEMP FIBER COMPOSITE PANELS Rahul, Raj; Shafi, K A Natural fibres have been outstanding materials which are feasible and amble substitute for expensive, non-bio degradable and non-renewable synthetic materials so these organic/natural fibres can be used as replacement for synthetic fibers for various applications. Cryogenic treatment is a type of heat treatment process applied to materials at low temperatures in which fiber is treated at cryogenic temperatures, at this low temperature conditions, materials showcase some physiochemical changes The main objective of these works is to conduct cryogenic treatment on hemp fiber and to study the effect of cryogenic treatment on thermal, mechanical and water absorption properties of hemp fiber reinforced epoxy composite panels. Physical properties such as functional groups of fabrics were studied and compared using Fourier Transform Infrared Spectroscopy (FTIR). It shows treatment on fiber have substantially increased the number of hydrogen bonding in cellulose, which lead to increase in stiffness of the fabric. The thermal behaviour of untreated and treated hemp fiber was studied using the techniques of thermo gravimetric analysis (TGA) and differential thermo gravimetric analysis (DTG). It is observed that after cryogenic treatment, hemp fiber's thermal stability has been significantly enhanced. Mechanical properties such as tensile and flexural strength of Hemp/epoxy panels are studied under untreated and cryogenic treated condition and the result show improvement in mechanical properties under cryogenic treatment. Improvement in mechanical properties was observed in cryogenic treated hemp composite due to increased frictional bond in the composite interface. Thermal conductivity of panels was measured using guarded hot plate method and the results shows decrease in thermal conductivity after cryogenic treatment. Water absorption rate of the fiber increases with time due to hygroscopic nature of fiber.Cryogenic treated hemp fiber shows 12% reduction in percentage of water absorption compared to untreated hemp fiber. These findings indicate hemp fabric as an alternative bio degradable material with greater thermal stability and physical qualities than synthetic materials for engineering applications

2023-05-01T00:00:00Z Sohail, Khan S Shafi, K A http://210.212.227.212:8080/xmlui/handle/123456789/464 2023-10-07T07:04:05Z 2023-05-01T00:00:00Z

INVESTIGATION ON TOOL LIFE AND HOLE QUALITY OF INCONEL 718 IN DRILLING OPERATION USING LN2 AS COOLANT Sohail, Khan S; Shafi, K A The main focus of the research was to investigate the process of machining Inconel 718 alloy using a Tungsten Carbide tool with a diameter of 6mm. Inconel 718 is a challenging material to machine due to its hardness and low thermal conductivity. The research aimed to enhance the quality of the hole surface while drilling Inconel 718. To achieve this, experiments were conducted using a Carbide tool under different cutting speeds, with both dry and cryogenic cooling conditions. The quality of the hole surface was then evaluated using SEM images and compared between the two conditions. The cutting speeds used in the experiments were 700rpm, 900rpm, and 1100rpm.The results of the experiments revealed that drilling Inconel 718 under dry conditions produced poor surface quality due to the generation of heat during the process. On the other hand, drilling under cryogenic conditions resulted in better hole surface quality. Additionally, the thrust force during drilling was greater under cryogenic conditions compared to dry conditions. These findings suggest that cryogenic cooling can be a useful method for enhancing the hole surface quality when drilling Inconel 718, and this method can be applied in industrial settings to improve the efficiency of the machining process.

2023-05-01T00:00:00Z Abhijith, A Shafi, K A http://210.212.227.212:8080/xmlui/handle/123456789/463 2023-10-07T07:00:05Z 2023-05-01T00:00:00Z

INVESTIGATION ON THE CAPACITANCE FLOW METER AND DEVELOPMENT OF VOID FRACTION SENSOR FOR CRYOGENIC TWO-PHASE FLOW Abhijith, A; Shafi, K A INVESTIGATION ON THE CAPACITANCE FLOW METER AND DEVELOPMENT OF VOID FRACTION SENSOR FOR CRYOGENIC TWO-PHASE FLOW

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