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Parsons, S R

Publications and source records attributed to Parsons, S R.

Properties of Special Types of Radiators

This report discusses the general performance characteristics of three special classes of radiators: those with flat plate water tubes, fin and tube types, and types that whistle in an air stream. Curves and tables show the performance of representative radiators of each class and compare the flat plate and whistling types. Empirical equations are given for estimating the performance of flat plate radiators of various dimensions. This report also contains a brief discussion, with curves, showing the effect of yawing on the properties of a radiator.

Parsons, S R↗

Effects of nature of cooling surface on radiator performance

This report discusses the effects of roughness, smoothness, and cleanness of cooling surfaces on the performance of aeronautic radiators, as shown by experimental work, with different conditions of surface, on (1) heat transfer from a single brass tube and from a radiator; (2) pressure drop in an air stream in a single brass tube and in a radiator; (3) head resistance of a radiator; and (4) flow of air through a radiator. It is shown that while smooth surfaces are better than rough, the surfaces usually found in commercial radiators do not differ enough to show marked effect on performance, provided the surfaces are kept clean.

Parsons, S R↗

Pressure Drop in Radiator Air Tubes

This report describes a method for measuring the drop in static pressure of air flowing through a radiator and shows (1) a reason for the discrepancy noted by various observers between head resistance and drop in pressure; (2) a difference in degree of contraction of the jet in entering a circular cell and a square cell; (3) the ratio of internal frictional resistance to total head resistance for two representative types; (4) the effect of smoothness of surface on pressure gradient; and (5) the effects of supplying heat to the radiator on pressure gradient. The fact that the pressure gradients are found to be approximately proportional to the square of the rate of flow of air appears to indicate turbulent flow, even in the short tubes of the radiator. It was found that the drop in the static pressure in the air stream through a cellular radiator and the pressure gradient in the air tubes are practically proportional to the square of the air flow in a given air density; that the difference between the head resistance per unit area and the fall of static pressure through the air tubes in radiators is apparent rather than real; and that radiators of different types differ widely in the amount of contraction of the jet at entrance. The frictional resistance was found to vary considerably, and in one case to be two-thirds of the head resistance in the type using circular cells and one-half of the head resistance of the radiator type using square cells of approximately the same dimensions.

Parsons, S R↗

Head Resistance Due to Radiators

Part 1 deals with the head resistance of a number of common types of radiator cores at different speeds in free air, as measured in the wind tunnel at the bureau of standards. This work was undertaken to determine the characteristics of various types of radiator cores, and in particular to develop the best type of radiator for airplanes. Some 25 specimens of core were tested, including practically all the general types now in use, except the flat plate type. Part 2 gives the results of wind tunnel tests of resistance on a model fuselage with a nose radiator. Part 3 presents the results of preliminary tests of head resistance of a radiator enclosed in a streamlined casing. Special attention is given to the value of wing radiator and of the radiator located in the open, especially when it is provided with a properly designed streamlined casing.

Kleinschmidt, R V↗

Effect of altitude on radiator performance

As an airplane rises to high altitudes the decrease in the density and the temperature of the air have important effects on the performance of the radiator. This report gives the results of a study of the effect of reduced pressure and temperature upon the capacity of airplane radiators. A method is presented by which the performance of a radiator at an altitude may be estimated for a particular speed of the airplane at a particular altitude.

James, W S↗