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Fundamentals of transportation engineering
280
BOOK
REVIE ws
carbon Combustion, Guenther vonElbe. 10. Space Heating Rates and High Temeprature Kinetics, W. H. Avery. 11. A Theory of Space Requirements for Combustion Behind Grids in a Closed Duet, Joseph Jennissen. The above survey papers include discussions of combustion instability with’ special reference to liquid and solid propellant rockets. This problem has plagued engineers since the beginning of modern rocket development. The introduction by Professor Hoyt C. Hottel is especially pertinent in which he states “the adequacy of our engineering knowledge of combustion is for engineering purposes in large measure tested by our ability to determine the space requirement for combustion” ; and this is directly or indirectly the subject of many of the papers. In reviewing these papers it is obvious that considerable progress has been achieved in correlating the reactivity of complex hydrocarbon molecules within the processes of energy transfers among the bands within the molecule. About half of the 45 contributed papers on chemical kinetics deal with the combustion of hydrocarbons. This book is indispensable as a reference source of information to anyone in the comF. L. JACKSON bustion field. FUNDAMENTALSOF TRANSPORTATION ENGINEERING,by Robert
G. Hermes and Martin I. Ekse. 520 pages, diagrams, 16 X 24 cm. New York, McGraw-Hill Book Co., Inc., 1955. Price, $8.50.
This book covers an ambitious program in various fields of transportation, mainly viewed from the civil engineering aspect. It includes road building and highway location, airport layouts and runways, railroad engineering with discussions on permanent way and motive power performance characteristics, rivers and harbors, and, finally, pipe lines and belt conveyors. The book is mainly of a descriptive nature, though some preliminary design data are included. In the opinion of the reviewer, the book is not a fundamental exposition on the various phases in transportation engineering. It ia-
[J. F. I.
eludes compiled data, but without careful analysis and interpretation. In the section on railroad engineering pertaining to locomotive performance, the A. R. Eng. Assoc. performance data are used, without any technical discussion of the limitation The power curves in of these formulas. terms of horsepower per ton on drivers is an assumed “statistical” exponential curve in terms of a speed ratio, where the basic speed is determined at the point where the maximum adhesion output per ton at drivers equals 0.632 of 80 per cent of the rated output per ton at drivers. The validity of this method is at best questionable, since the relation of adhesion limits and power capacity are fairly arbitrary. The continuous rating depends upon the heating limitations and motor proportions. The continuous torque at rated speed gives the rated output and this is limited by engine output. The starting tractive force, in turn, depends upon the permissible overload torque relative to its continuous rating and this in turn must be compatible with limiting adhesion. The speed range, physically, is some definite factor of the continuous rating speed. The output characteristics of modern Diesel electric locomotion is more nearly of a constant output curve against speed except in the adhesion or starting range, where the output increases nearly linearly with speed, and at extreme speeds where there is some falloff in power. Again with steam locomotives, cylinder performance is limited by boiler capacity. With adequate boiler capacity, cylinder performance gives very closely a linear dropoff in tractive force and a corresponding parabolic power curve and not an exponential curve. Again, a more fundamental analysis is needed to even approximately arrive at the performance characteristics of a locomotive. The danger of a book of this type, in seeking an over-all review of fundamentals, is the inadequacy of space for a careful and sufficient presentation of the topics considered, and the necessity of presenting much statistical and catalogue data for some, without sufficient analysis for its justification. RUPEN EKSERGIAK
BOOK
REVIE ws
carbon Combustion, Guenther vonElbe. 10. Space Heating Rates and High Temeprature Kinetics, W. H. Avery. 11. A Theory of Space Requirements for Combustion Behind Grids in a Closed Duet, Joseph Jennissen. The above survey papers include discussions of combustion instability with’ special reference to liquid and solid propellant rockets. This problem has plagued engineers since the beginning of modern rocket development. The introduction by Professor Hoyt C. Hottel is especially pertinent in which he states “the adequacy of our engineering knowledge of combustion is for engineering purposes in large measure tested by our ability to determine the space requirement for combustion” ; and this is directly or indirectly the subject of many of the papers. In reviewing these papers it is obvious that considerable progress has been achieved in correlating the reactivity of complex hydrocarbon molecules within the processes of energy transfers among the bands within the molecule. About half of the 45 contributed papers on chemical kinetics deal with the combustion of hydrocarbons. This book is indispensable as a reference source of information to anyone in the comF. L. JACKSON bustion field. FUNDAMENTALSOF TRANSPORTATION ENGINEERING,by Robert
G. Hermes and Martin I. Ekse. 520 pages, diagrams, 16 X 24 cm. New York, McGraw-Hill Book Co., Inc., 1955. Price, $8.50.
This book covers an ambitious program in various fields of transportation, mainly viewed from the civil engineering aspect. It includes road building and highway location, airport layouts and runways, railroad engineering with discussions on permanent way and motive power performance characteristics, rivers and harbors, and, finally, pipe lines and belt conveyors. The book is mainly of a descriptive nature, though some preliminary design data are included. In the opinion of the reviewer, the book is not a fundamental exposition on the various phases in transportation engineering. It ia-
[J. F. I.
eludes compiled data, but without careful analysis and interpretation. In the section on railroad engineering pertaining to locomotive performance, the A. R. Eng. Assoc. performance data are used, without any technical discussion of the limitation The power curves in of these formulas. terms of horsepower per ton on drivers is an assumed “statistical” exponential curve in terms of a speed ratio, where the basic speed is determined at the point where the maximum adhesion output per ton at drivers equals 0.632 of 80 per cent of the rated output per ton at drivers. The validity of this method is at best questionable, since the relation of adhesion limits and power capacity are fairly arbitrary. The continuous rating depends upon the heating limitations and motor proportions. The continuous torque at rated speed gives the rated output and this is limited by engine output. The starting tractive force, in turn, depends upon the permissible overload torque relative to its continuous rating and this in turn must be compatible with limiting adhesion. The speed range, physically, is some definite factor of the continuous rating speed. The output characteristics of modern Diesel electric locomotion is more nearly of a constant output curve against speed except in the adhesion or starting range, where the output increases nearly linearly with speed, and at extreme speeds where there is some falloff in power. Again with steam locomotives, cylinder performance is limited by boiler capacity. With adequate boiler capacity, cylinder performance gives very closely a linear dropoff in tractive force and a corresponding parabolic power curve and not an exponential curve. Again, a more fundamental analysis is needed to even approximately arrive at the performance characteristics of a locomotive. The danger of a book of this type, in seeking an over-all review of fundamentals, is the inadequacy of space for a careful and sufficient presentation of the topics considered, and the necessity of presenting much statistical and catalogue data for some, without sufficient analysis for its justification. RUPEN EKSERGIAK