Experiment Research On Hydrocarbon Compounds’ Viscosity Of High Temperature By Double-capillary Tube Method

Fuel research is an important part of the study of hypersonic vehicle technology. Hydrocarbon fuel had become the first choice for hypersonic vehicle fuel, because hydrocarbon fuel has unique advantages, such as low density, high energy, wide source and low price. Before researching the characteristics of fuel, to research the properties of fuel was premise. This paper was based on the law of Hagen-Poiseuill law, the viscosity of hydrocarbon fuel was tested by double capillary method. In order to realize the testing requirements of high temperature working conditions and to improve the test precision, the existing experiment platform of double capillary method was improved and optimized. Temperature control system was the focus of improvement, the installation of two sets of constant temperature system which was controlled by automatic temperature controller; and in order to reduce the experimental error, the structure of the test side was optimized, and got the error correction. The experiment platform was not only used for testing viscosity of the higher temperature hydrocarbon fuel, but also could be used to measure other Newton liquid in higher temperature conditions of the viscosity.The toluene, twelve alkanes and octane/heptane(mass ratio is 1:1 mixture) were calibration objects, compared to the intermediate volume conversion method and thermal expansion method, finally, the intermediate conversion method was chosen for calculating the data of the experiment, the centrifugal force was the main source of error and the centrifugal correction method was given. Based on that, the viscosity of several hydrocarbon compound fuel were measured, the pressure conditions were 3~5MPa and the temperature conditions were 250~400℃, the viscosity test curves were drew under different temperature conditions and different pressure conditions, temperature and fuel composition were the main factors influencing hydrocarbon compound fuel viscosity values, hydrocarbon fuel viscosity value increased with the increase of temperature, the different components of the hydrocarbon fuel viscosity varied greatly, and pressure was not main factor to effect the viscosity value of hydrocarbon compound fuel, finally calculated the uncertainty was 1.00% of this experiment.