Scaled Apollo Capsule Heat Flux Measurements in the X3 Expansion Tube

State-Specific Study of Air in the Expansion Tunnel Nozzle and Test Section

“…The value of dci/dx is proportional to ρ for the VT and VVT reactions, and the value of dci/dx is proportional to ρ 2 for the recombination reactions. Since p is proportional to ρ according to the ideal gas law, the aforementioned trends for ρ can also be said for p. In the expansion tunnel, the nozzle inlet pressure typically ranges from around 10 kPa to 100 kPa [94][95][96][97], while the nozzle inlet velocity typically ranges from around 4 km/s to 11 km/s [95,98,99]. Based on these conditions and the discussion on the dependencies of dci/dx, we can see that it is the range of the inlet pressure (an order of magnitude, which is much higher than the factor of 2-3 for the range of the inlet velocity) which would determine the variety of different thermochemical behaviors (equilibrium, frozen, nonequilibrium) that are possible in the expansion tunnel nozzle.…”

“…Therefore, evaluations of the discrepancy between the 2T and StS models are carried out for the entire range of the inlet pressure. The nozzle inlet temperature typically ranges from around 1000 K to up to 4000 K [95,100]. However, the StS reaction rates determined from the FHO theory, which are used in this work, are less accurate at low temperatures (≲ 1000 K) due to pronounced quantum effects (such as anti-Arrhenius behavior) which are not accounted for [53,101].…”

Измерение Нестационарного Теплового Потока В Экспериментах На Ударных Трубах С Помощью Датчиков На Основе Анизотропных Термоэлементов Из Висмута

“…Измерение теплового потока к поверхности тела, обтекаемого высокоэнтальпийным потоком газа, является базовой диагностикой в аэрофизическом эксперименте, поскольку позволяет получить интегральную характеристику процессов теплообмена в ударном слое [1][2][3]. В условиях наземного эксперимента достаточно полное воспроизведение условий реального высокоскоростного полета возможно лишь на установках импульсного действия с рабочим временем ∼ 1−10 ms [1,2,4,5]. Поэтому основными требованиями к тепловым датчикам являются высокое быстродействие ∼ 1 µs при общей длительности регистрации в течении ∼ 10 ms и диапазон измерений от ∼ 100 kW/m 2 до ∼ 10 MW/m 2 .…”

Non-stationary heat flux measurement in shock tube experiments using sensors based on anisotropic bismuth thermoelements

“…Measuring the heat flux to the surface of a body flown by a high-enthalpy gas flow is the basic diagnostics in an aerophysical experiment, since it allows one to obtain an integral characteristic of heat transfer processes in the shock layer [1][2][3]. Under the conditions of a groundbased experiment, a fairly complete reproduction of the conditions of a real high-speed flight is possible only on pulsed gasdynamic facilities with an operating time of ∼ 1−10 ms [1,2,4,5]. Therefore, the main requirements for thermal sensors are high speed ∼ 1 µs with a total recording duration of ∼ 10 ms and a measurement range from ∼ 100 kW/m 2 to ∼ 10 MW/m 2 .…”