d. k. singh

In a centrifugal pump, the clearance flow is quite common due to the existence of clearance between the casing and impeller. Apart from the clearance, the impeller speed and flow rate have a significant impact on fluid frictional torque. This study uses experimental and numerical methods to investigate these dynamics. The experimental setup includes measurements of fluid frictional torque at various levels of axial clearance (0.6 mm, 1.2 mm, and 1.8 mm), flow rates (8 L/min, 10 L/min, and 12 L/min), and impeller speeds (800 rpm, 1000 rpm, and 1200 rpm). A 3-level, 3-factor factorial design (L27) is employed to systematically examine the impact of these factors on fluid frictional torque. Response Surface Methodology (RSM) and Artificial Neural Networks (ANNs) are utilized to capture complex parameter interactions, with optimization performed using a Desirability Function (DF). The analysis reveals a significant increase in fluid frictional torque with increasing axial clearance, impeller speed, and flow rate. The optimal operational parameters for minimizing fluid frictional torque in the centrifugal pump are identified as    and mm, achieving a minimum fluid frictional torque of 0.499 Nm

This study was conducted to examine the sensitivity of weather parameters and CO2 concentration to wheat production under two irrigation regimes viz. full irrigation and limited irrigation, using CERES-Wheat model. Field experiment data from the 2016-17 and 2017-18 rabi seasons on wheat cultivar HD-2967 with three sowing dates and five irrigation regimes were used to calibrate and validate the CERES-Wheat crop simulation model. Validation results indicated very good agreement between simulated and observed values under five, four, and three irrigations regimes as compared to lower irrigation regimes. Under full irrigation and limited irrigation, grain yield sensitivity to incremental unit of mean temperature from 1 to 3°C revealed a decrease of 6 to 22% and 8 to 16%, respectively. Temperature decreases of 1-3°C resulted in a gradual increase in yield of 10-28 and 6.5- 20%, respectively, under full and limited irrigation. The combined effect of higher mean temperature and lower solar radiation revealed that wheat yield was more sensitive to temperature than solar radiation. Furthermore, the combined effect of mean temperature and CO2 level revealed that higher levels of CO2 concentration yielded the greatest benefits with a 1 °C increase in temperature, but further increases in temperature reduced the beneficial effect of elevated CO2 level under both irrigation conditions.