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This paper aims to determine the regression rate using wax fuels for three different grain configurations and find a suitable grain port design for hybrid rocket application.

The design methodology of this work includes different grain port designs and subsequent selection of solid fuels for a suitable hybrid rocket application. A square, a cylindrical and a five-point star grained were designed and prepared using paraffin and beeswax fuels. They were tested in a laboratory-scale rocket with gaseous oxygen to study the effectiveness of solid fuels on these grain structures. The regression rate by static fire testing of these wax fuels was analyzed.

Beeswax performance is better than that of paraffin wax fuel for all three designs, and the five-slotted star fuel port grain attained the best performance. Beeswax fuel attained an average regression rate ≈of 1.35 mm/s as a function of oxidizer mass flux Gox ≈ 111.8 kg/m² s and for paraffin wax 1.199 mm/s at Gox ≈ 121 kg/m² s with gaseous oxygen. The local regression rates of fuels increased in the range of 0.93–1.194 mm/s at oxidizer mass flux range of 98–131 kg/m² s for cylindrical grain, 0.99–1.21 mm/s at oxidizer mass flux range of 96–129 kg/m2s for square grain and 1.12–1.35 mm/s at oxidizer mass flux range of 91–126 kg/m² s for a star grain. A complete set of the regression rate formulas is obtained for all three-grain designs as a function of oxidizer flux rate.

The experiment has been performed for a lower chamber pressure up to 10 bar.

Different grain configurations were designed according to the required dimension of the combustion chamber, injector and exhaust nozzle of the design of a lab-scale hybrid rocket, and input parameters were selected and analyzed.

The purpose of this study is to investigate the physical, chemical and thermal characteristics of paraffin-blended fuels to determine their suitability as fuel in hybrid rockets.

Wax fuels are viable and efficient alternatives to conventional rocket fuels, having excellent structural strength and thermal and mechanical properties. The authors report a study of the morphological, chemical and thermal properties of paraffin wax with and without additives for use as fuels in hybrid rockets. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were used for the morphological and chemical characterizations of the fuel blends. The thermal stability and combustion characteristics were assessed under an atmosphere of nitrogen by the simultaneous application of thermogravimetry and differential scanning calorimetry techniques.

The melting temperatures for pure paraffin and other formulations were around 61°C as seen in differential scanning calorimetry experiments. Variations in the compositions of monoesters, n-alkanes, fatty acids, carboxylic acids methyl and hydroxyl esters in the fuel samples were assessed using Fourier transform infrared spectroscopy. The assessment criterion was chosen as the relative content of carbonyl groups, and the ratio of the stretching vibration of the C–C bonds to the deformation vibration of the aliphatic carbon–hydrogen bonds was taken as the basis for the quantitative calibration. The crystal phases identified by X-ray diffraction were used to identify nonlinear chemicals and alkane lengths. Scanning electron microscopy validated homogeneity in the paraffin-blended samples.

This study presents the thermal stability and other relevant characteristics of fuel formulations comprising unconventional blends.

IN COUNTRIES where sub‐arctic conditions can occur during the winter months, the cost of maintaining the engine jacket water above freezing point is a major item, particularly on diesel engines used for rail traction purposes. The addition of anti‐freeze to the water system is expensive and unless a close watch is kept on the concentration, trouble can occur in the way of cracked crank cases, radiator water elements, etc., etc.

In the case of stationary fuel tanks subjected to high ambient temperatures for prolonged periods, vaporization may account for a significant loss of the more volatile fractions. Although the quantitative loss might not be serious, fuel quality may be affected to the extent of difficult starting under subsequent low temperature conditions.

Flight, even under the most routine conditions, sets high standards of quality for all materials employed. Specifications for aviation fuels have never been obtainable without careful compromise between conflicting requirements, and present developments towards flight at higher altitudes and higher speeds accentuate existing problems and reveal new ones. This article attempts to review the known major problems arising with aviation fuels under these conditions of severity, and to indicate a number of practicable solutions.

TWO NEW PLANTS have recently been placed on stream by the Standard Oil Company (Indiana) in the United States for the production of lubricating oil by modern methods. One, at the company's Whiting, Indiana, refinery, consists of a 5,800 bbl/day (average) dewaxing, 2,800 bbl/day (average) deoiling unit for treating waxy oil feed. The other is at Casper, Wyoming, for treating Salt Creek Green Wyoming crude oil. Here, the vacuum distillation unit has a throughput capacity of 11,500 bbl/day. Both plants use the MEK (Methyl‐ethyl‐ketone) dewaxing‐deoiling process licensed by Texaco Development Corpn. In both cases, the plants were built by the Foster Wheeler Corpn., who also supplied the process and mechanical design.

Wear can be minimised by good lubrication. We have travelled far since lubrication meant just “oil”; refining processes have improved, oils are more “oily”, and additives reduce the effects of gums, oxidation, acid formation, etc., over a useful service life. Extreme pressure agents and detergents allow operation under conditions of load and temperature not possible with straight oils. Yet all these advances count for little, unless abrasives are excluded.

The Basic Design Philosophy as it Applies to all Load‐Carrying Elements including a Description of Fuel Tank Design, Flap Structure and Floor Layout. FROM the structural viewpoint the aircraft had to suit the needs of the small or medium‐sized airline having difficult operating conditions. Structural integrity would have to be maintained with limited servicing facilities and the aircraft must be capable of operating in remote areas from rough airstrips. Therefore, this meant that the aircraft had to have a high degree of reliability and serviceability, be of rugged construction with a long fatigue life, be designed for easy maintenance on a scheduled inspection basis, and have quick turn round times using the minimum of staff and facilities.