Effect of Variation of Intake Depths on Water Injection Temperatures.
Abstract
Water intake temperature errors generally fall into one of the following major categories: (1) Engine room heating, (2) Observer error, (3) Coding error, (4) Depth of water intake. Although high engine room temperatures are often suggested as positively biasing intake temperature, this conclusion is not supported by facts. Observer errors in reading the thermometer is undoubtedly the major cause of large temperature errors in injection readings and can be eliminated only by use of a better sensing system. Coding errors are significant but offer the best possibility for correction. Since many classes of ships report water temperatures and because each class has a different type of hull with a particular depth of water intake, errors occur in reported water temperatures because of the variation in sampling depths. By use of the tables and figures in this study, it is possible to determine temperature errors between 0 and 11.5 F. The average annual temperature error is only 0.033 F, and vertical gradients at the surface were less than 1.0 F per 20 feet 94 percent of the time. At this gradient, the average temperature error was only 0.165 F, and the absolute error for all intake depths ranged between zero and 0.6 F. This latter error could be halved by limiting installation to 75 percent of the ships. This study concludes that it is feasible to utilize the intake system as a means of improving the accuracy of sea surface temperature observations for operational utilization.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1964
- Accession Number
- ADA035012
Entities
People
- Mitchell K. Shank Jr
- Richard W. James
Organizations
- Naval Oceanographic Office