Muneesh Sethi

Experimental investigation of effect of flow attack angle on thermohydraulic performance of air flow in a rectangular channel with discrete V-pattern baffle on the heated plate

In this work, the effect of angle of attack ( α a ) of the discrete V-pattern baffle on thermohydraulic performance of rectangular channel has been studied experimentally. The baffle wall was constantly heated and the other three walls of the channel were kept insulated. The experimentations were conducted to collect the data on Nusselt number ( N u b ) and friction factor ( f b ) by varying the Reynolds number (Re) = 3000–21,000 and angle of attack ( α a ) from 30° to 70°, for the kept values of relative baffle height ( H b / H ) = 0 . 50 , relative pitch ratio ( P b / H ) = 1 . 0 , relative discrete width ( g w / H b ) = 1 . 5 and relative discrete distance ( D d / L v ) = 0 . 67 . As compared to the smooth wall, the V-pattern baffle roughened channel enhances the Nusselt number ( N u b ) and friction factor ( f b ) by 4.2 and 5.9 times, respectively. The present discrete V-pattern baffle shapes with angle of attack ( α a ) of 60° equivalent to flow Reynolds number of 3000 yields the greatest thermohydraulic performance. Discrete V-pattern baffle has improved thermal performance as compared to other baffle shapes’ rectangular channel.

Single-phase thermal and hydraulic performance analysis of a V-pattern dimpled obstacles air passage

ABSTRACT This work deals with the experimental investigation on heat transfer, friction factor, and thermal hydraulic performance of V-pattern dimpled obstacles in an air passage. The experiments were conducted in a turbulent flow regime with Reynolds number ranging from 5,000 to 17,000 using air as the working fluid under uniform wall heat flux boundary condition. The experimental investigation encompassed the geometrical parameter, namely relative dimpled obstacles width varying from to , ratio of dimpled depth to print diameter () from 0.50 to 2.0, relative dimpled pitch () from 8.0 to11.0, relative dimpled height of 0.037, and the angle of attack () varying from 35° to 75°. The experimental results revealed that both heat transfer and friction factor of the air passage fitted with the V-pattern dimpled obstacles were significantly higher than those of the smooth-surface air passage. The optimum data of thermal and hydraulic performance were obtained at , 1.0, = 9.0, = 0.037, and = 55°. The current study shows that the thermal hydraulic performance of multi-type V-pattern dimpled obstacles shape is around 7% higher as compared to other obstacles shapes air passage.

EXPERIMENTAL INVESTIGATION ON OVERALL THERMAL PERFORMANCE OF FLUID FLOW IN A RECTANGULAR CHANNEL WITH DISCRETE V-PATTERN BAFFLE

This work presents the results of an experimental study of thermo-hydraulic performance of rectangular channel having discrete V-pattern baffle attached on the broad wall. Measurements have been carried out for the aspect channel ratio of 10, Reynolds number from 3000 to 21000, relative baffle height value of 0.50, relative baffle pitch value of 1.5, relative gap width value of 1.0, flow attack angle value of 60°, relative discrete distance values of 0.26 to 0.83. The heat transfer and friction factor data obtained were compared with the data obtained from a smooth wall channel under similar operating conditions. In comparison to the smooth wall channel the discrete V-pattern baffle channel enhanced the Nusselt number and friction factor by 3.89 and 6.08 times, respectively. The overall thermal performance parameter is found superior for the relative discrete distance of 0.67. Discrete V-pattern baffle roughness shape has also been shown to be overall thermal performance higher in comparison to other continuous (without discrete) V-pattern baffle shape rectangular channel.

Micronutrients distribution in salt-affected soils of the Punjab in relation to soil properties

Salt-affected soils in arid and semi-arid tracts of the Indian Punjab are prone to deficiency of micronutrients. Nine profiles from alluvial terraces, sand dunes and palaeochannels in the southwestern Punjab were investigated for total and diethylenetriamine-penta-acetic acid (DTPA) extractable Zn, Cu, Mn and Fe. Soil physiography exerted significant influence on the spatial distribution of micronutrients. Total contents varied from 20–78 for Zn, 8–32 for Cu, and 88–466 mg kg−1 for Mn and 0.82–2.53% for Fe. DTPA-extractable contents varied from 0.10–0.98 for Zn, 0.14–1.02 for Cu, 0.54–13.02 for Fe and 0.82–9.4 mg kg−1 for Mn. Total contents were higher in fine-textured soil than in coarse-textured soils. Concentration of micronutrients in the surface layer was low and there occurred more accumulation in the Cambic horizon. Organic carbon, pH, clay, silt and calcium carbonate exerted strong influence on the distribution of micronutrients. DTPA extractable Zn, Cu, Mn and Fe increased with increasing organic carbon but decreased with increase in pH and calcium carbonate content. Total micronutrient contents increased with increase in clay, silt and calcium carbonate contents and decreased with increase in sand content.

Impact of Sand Erosion on Hydroturbines: A Case Study of Hydropower Plant in Himachal Pradesh, India

Sand erosion is the system of unfaltering avoidance of the solid from the surface of the hydroturbine hardware which relies on the concentration, size, hardness of sand particles, stream speed, and properties of material of different parts of turbine and working hours of the turbine. It is one of the major and complex issues in Himalayan area particularly amid storm season. Various investigations on erosion of turbine have demonstrated that the material of turbine apparatus dissolved because of sand particles. This paper depicts the exhaustive examination of silt, disintegration of runner cutting edges, and guide vanes of 300 MW Chamera-II hydrocontrol plant. It has been observed that hardness, size, and shape are vital parameters concerning their impacts on disintegration of water-driven turbines. Ultimately, weight lessening of turbine and subsequent fall in the productivity of force plant because of residue disintegration was likewise investigated.