Publisher: RareBooksClub.com (May 9, 2012)
Format: PDF / Kindle / ePub
Size: 8 MB
Downloadable formats: PDF
This ancient booklet can have a variety of typos and lacking textual content. dealers can obtain a loose scanned reproduction of the unique ebook (without typos) from the writer. now not listed. now not illustrated. 1902 Excerpt: ... race.--The motion of the screw-propeller is to force sternward a cylindrical column of water, frequently known as the 'propeller race,' and the thrust of the screw is measured by means of the sternward momentum generated during this race in a unit of time. the realm of this race is nearly equivalent to that of the screw disc, much less that of the boss of the screw, the race being in reality nearly a revolving annular column. as a result of the obliquity of the propelling surfaces, the race gets a rotatory in addition to a sternward movement, and this centrifugal motion factors a definite lack of thrust. The race of a screw-propeller might be conceived to be a sequence of concentric cylinders of water relocating sternward, and rotating at assorted velocities. it really is glaring that the thrust needs to be decreased either through the centrifugal movement and by means of the frictional motion of the debris of water. Augmentation of resistance because of motion of screw-propeller.--The most vital characteristic within the motion of a screw-propeller, as affecting its potency, is the influence it produces at the water below the strict of the send. within the absence of the propeller the water displaced on the bow by way of the passage of a good shaped send, may shut in lower than the strict and reason a ahead strain there. The motion of the screw withdraws this water, and accordingly diminishes the strain of water below the strict, that is such as expanding the resistance of the send, in comparison with the average resistance, or the resistance skilled by way of the send while towed on the related pace. The resistance augmentation varies highly, reckoning on the form of the strict of the send and the scale and place of the screws quite to the vessel. The overdue Mr. Froude experimented, and regarded approximately forty consistent with cent...