Isobaric Specific Heat Capacity And Viscosity Measurement For An Endothermic Hydrocarbon Fuel

The choice of fuel is an important part of the study of hypersonic aircraft and it has been widely used. Endothermic hydrocarbon fuel has the characteristics of high density and high heat capacity. In recent years, as a hypersonic flight vehicle fuel, it has gradually become a development trend. When studying flow and heat transfer characteristics of endothermic hydrocarbon fuel, physical parameters is the most basic research, For example, isobaric specific heat capacity and viscosity is the basic data for the engineering application of science, but due to the complexity of hydrocarbon fuel components, experimental testing is a reliable way for thermal physical parameters. We need to establish new methods and new instruments.a specific heat measurement system and a viscosity measurement system were designed and optimized respectively. The pure were used to verify the reliability and accuracy of the measurement. The specific heat capacities of the hydrocarbon fuel were measured at subcritical(2.0MPa) and supercritical(3.5MPa, 5.0MPa) pressures with a temperature range of 333 to 903 K. The viscosities of the hydrocarbon fuel were measured at 3.0MPa-5.0MPa pressures with a temperature range of 303 to 513 K. The varied curves of heat capacities and viscosities were obtained at test conditions.This paper analyzes temperatures, pressures and fuel compositions which effects on isobaric specific heat capacity and viscosity. The results showed that different isobaric specific heat capacity and viscosity of hydrocarbon fuels have similar trends. In the low temperature specific heat increased gradually as temperature increased, and got its first peak value when temperature reached the critical or pseudocritical value. At high temperature, the endothermic chemical reactions appeared and the specific heat increased with the temperature rose. Viscosity increased quickly as temperature increased, and decreasing trend was gradually slow. The first peak value of specific heat gradually diminished with the pressure increased. However, the specific heat was enlarged with the increase of pressure at high temperature. At the same temperature, viscosity rose as the pressure increased. At the same pressure, isobaric specific heat capacities were different when temperature reached the critical or pseudocritical value. Different hydrocarbon fuels also presented different viscosity values. The conclusion of the paper has a high application value for producting, testing and evaluating fuel.