Formula Used:
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The Specific Gas Constant (R) is a fundamental property of a particular gas that represents the amount of energy required to raise the temperature of one unit of the gas by one degree Kelvin (or Celsius) per unit mass. It is derived from the universal gas constant and the molar mass of the specific gas.
The calculator uses the formula:
Where:
Explanation: This formula relates the specific gas constant to various aerodynamic and thermodynamic parameters, allowing calculation of R from measurable flow properties.
Details: The specific gas constant is crucial in thermodynamics and fluid dynamics calculations. It appears in the ideal gas law, isentropic flow equations, and various other thermodynamic relationships. Accurate determination of R is essential for precise calculations involving gas properties and behavior.
Tips: Enter dynamic pressure in Pascals, ambient air density in kg/m³, Mach number (dimensionless), heat capacity ratio (dimensionless), and static temperature in Kelvin. All values must be positive and valid for accurate results.
Q1: What is the difference between universal gas constant and specific gas constant?
A: The universal gas constant (R₀) is the same for all ideal gases (8.314 J/mol·K), while the specific gas constant (R) is unique to each gas and equals R₀ divided by the molar mass of the gas.
Q2: Why is the specific gas constant important in aerodynamics?
A: In aerodynamics, R is crucial for calculating various flow properties, including speed of sound, Mach number relationships, and isentropic flow equations that describe how pressure, temperature, and density change in compressible flows.
Q3: What are typical values of specific gas constant for common gases?
A: For air: approximately 287 J/kg·K; for helium: 2077 J/kg·K; for hydrogen: 4124 J/kg·K. The value varies significantly depending on the gas molecular weight.
Q4: How does temperature affect the specific gas constant?
A: For ideal gases, the specific gas constant is constant and does not change with temperature or pressure. It is a fundamental property of the gas itself.
Q5: Can this calculator be used for any gas?
A: Yes, the formula is general and can be applied to any ideal gas, provided you have accurate measurements of the input parameters for that specific gas.