02887nam a2200253   450000500170000000800410001703500150005810000200007324500610009326000520015430000220020649000260022850200580025450001070031252018460041965000200226570000360228570000440232170000460236570000410241171000580245281000580251085600650256820260818171601.0080598         th                  eng    a.b104952890 aNguyen Ba Quang10aPerformance of a powered disk in clay soil in a soil bin  aBangkok :bAsian Institute of Technology,c1994  a91 leaves :bill.1 aThesis ;vno. AE-94-9  aThesis (M.Eng.) - Asian Institute of Technology, 1994  aA thesis submitted in partial fulfilment of the i·equirement for the degree of Master of Engineering.  aExperiments were conducted in a laboratory soil bin having Bangkok clay soil with average moisture content of 18% (db) and cone index of about 1100 kPa. The disk having 510 cm diameter and 560 mm radius of concavity was used. Disk angle from 20 to 35°, ground speed from 1 to 3 km/h and rotational speed from 60 to 140 rpm were varied. The working depth was kept constant at 12 cm. It was observed that disk angle, rotational speed and ground speed had significant effect on soil reactive forces and power requirement. At small disk angle, low ground speed, and high rotational speed, the soil longitudinal reactive force was a pushing force and became a resistive one at larger disk angle and ground speed. The soil transverse reactive force increased with the increase of rotational and ground speed but decreased with the increase of disk angle, while the vertical reactive force increased only with the increase of ground speed but decreased with the increase of rotational speed and disk angle. It was found that the powered disk required smallest power at disk angle of 30° and rotational speed between 80 and 100 rpm. As ground speed increased, total power requirement increased. Increase in ground speed from 1 to 3 km/h increased the total power requirement by 31. 8 3 . At driving the disk forward, the draft reduced considerably as compared with that of the free rolling disk. By driving the disk in reverse direction the draft reduced slightly. At disk angle of 30°, rotational speed of 100 rpm, and ground speed of 3 km/h, the total power requirement of the forward driven disk was 65 % higher than that of the free rolling disk. The predicted engine power of the forward driven disk, however, was only 21 3 higher than that of the free rolling one owing to the more efficient power transmission through PTO than via drawbar. 0aDisks, Rotating1 aSalokhe, Vilas M.,eChairperson1 aSingh, Gajendra,eExamination Committee1 aClough, David Gee,eExamination committee1 aGupta, C. P.,eExamination committee2 aThe Government of The Netherlands,eScholarship donor2 aAsian Institute of Technology.tThesis ;vno. AE-94-9  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B15948