File Size895.75 KB
Tags   Engine     Fuel     Injection     NACA     Pressure     Vapor  
naca-report-321 Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines.pdfDownload 

National Advisory Committee for Aeronautics, Report - Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines

naca-report-321 Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines-1

This investigation on the vapor pressures of fuels was conducted at the Langley Memorial
Aeronautical Laboratory at Langley Field, Va., in connection with the general research on combus-
tion in fuel injection engines. The purpose of the investigation was to study the ejects of high
temperatures such as anist during the first stages of injection on the vapor pressures of seceral fuels
and certain fuel mixtures, and the relation of these vapor pressures to the preparation of the fuel for
combustion in high-speed fuel injection engines.

The apparattrs employed in the tests consisted of a gas-tight steel bomb, a Bourdon spring
pressure gauge, an electric furnace, a thermocouple, and a potentiometer. The bomb was par-
tially filled with the fuel to be tested, the space above the fuel filled with nitrogen to prevent
combustion, and the bomb heated in an electric furnace. Pressure and temperature readings
were taken simultaneously during the heating and cooling periods over a temperature range
from 175° to approximately 900° F. Vapor and gas pressures up to 5,000 pounds per
square inch were measured. The fuels tested were gasoline, kerosene, Diesel engine fuel oil,
ethyl alcohol, methyl acohol, benzol, mixtures of methyl alcohol and gasoline, and mixtures of
benzol and gasoline. An aircraft engine lubricating oil was also tested. Water was tested as
a standard in order to compare these results with those of other investigators. The conditions,
of the tests were similar to those met in the combustion chamber of a. fuel injection engine and
consequently the data apply to those conditions.

It was found that the vapor pressures of the fuels increased rapidly at high temperatures,
the rate of pressure increase becoming greater as the temperatures approached the critical
value. Beyond the critical temperature, the‘ rate of pressure increase was constant except at
one or more temperatures in the case of certain fuels and their vapors in which chemical changes
took place. The chemical changes in some of the fuels were such that the cooling curves were
materially different from those obtained during the heating periods. Permanent gases were
generated during the heating and cooling periods in the case of the alcohols, gasoline, kerosene,
and Diesel engine fuel oil so that the fuels removed from the bomb were materially difierent
from those placed in it. The vapor pressures of the fuels difiered from each other considerably,
methyl alcohol having the highest vapor pressure, 4,370 pounds per square inch, and Diesel
engine fuel oil the lowest, 14.0 pounds per square inch, for the maximum temperature investi—
gated, approximately 850° F.

Have A Comment On This Article? Post It Here.

Comments are moderated and will not be published until approved. Your email address will be kept confidential. Please review our Comment Policy before posting your comment.


Microsoft Excel Spreadsheets

FREE ANALYSIS SPREADSHEETS 3 Over the last 10 years we have developed hundreds of spreadsheet tools to help us with our structural analysis work. We have made these available through the Abbott Aerospace web site and the XL Viking project. We have now brought them into the technical library. They have been updated, improved and the collection has been expanded to cover more analysis methods than ever before.

The XL-Viking Add-In for Excel

XL-Viking 2 We created the XL-Viking Excel add-in to satisfy our own need to make Excel a better engineering tool. XL-Viking shows your Excel Formula in a way that makes sense and brings essential new functionality to Microsoft Excel by providing an additional user interface and easy to use functions.

The Indispensable Tool For Engineers, Mathematicians, Scientists, Accountants and Teaching Professionals!


Technical Papers & Reports

This is our collection of public domain references. All of the material we make available has been placed in the public domain by the authors/owners. If you believe this is not the case and any of the library material is not in the public domain please let us know. If you have any reference material that you would like to see included in the library we would love to hear from you.

Market Analysis and Market Information

Our newest addition to the library is an on-going series of articles on the aircraft and aerospace market. These are part quantitative and part qualitative and introduce a new aspect to the competencies within Abbott Aerospace.