International Steam Tables 與 HVAC engineering calculator 使用情況與統計

The "International Steam Tables - IAPWS-IF97" app has been developed by active members of the International Association for the Properties of Water and Steam (IAPWS) at the Zittau/Görlitz University of Applied Sciences. The research group at the Department of Technical Thermodynamics in Zittau participated in the development of the "Industrial Formulation IAPWS-IF97 for the Properties of Water and Steam" and developed four supplementary standards for backward equations. This universal app can be used on iPhone, iPad, and iPod touch, and is designed for comfortable use. The calculations of the thermodynamic properties are based on the Industrial Formulation IAPWS-IF97 and cover its full range of validity. In addition, transport properties, thermodynamic derivatives, and backward functions can be calculated. This app is intended to be used by students and engineers in their daily work. To learn more about the "International Steam Tables - IAPWS-IF97" app visit our website www.thermodynamics-zittau.de for a detailed User's Guide. --------------------------------------- Features of the "International Steam Tables - IAPWS-IF97" app: The following combinations of input variables can be chosen: Pressure p and temperature t Pressure p and vapor fraction x in wet steam region Temperature t and vapor fraction x in wet steam region Pressure p and specific enthalpy h Pressure p and specific entropy s Specific enthalpy h and specific entropy s Specific internal energy u and specific volume v Specific enthalpy h and specific volume v The user just edits the values of the input variables and all results are calculated automatically. See the screenshots below this text for details. Depending on the given pair of input variables the following properties will be calculated: Pressure p or saturation pressure ps Temperature t or saturation temperature ts Vapor fraction x Specific volume v Density rho Specific internal energy u Specific enthalpy h Specific entropy s Specific isobaric heat capacity cp Specific isochoric heat capacity cv Isentropic exponent kappa Speed of sound w Isobaric cubic expansion coefficient alpha_v Isothermal compressibility kappa_t Thermal conductivity lambda Dynamic viscosity eta Kinematic viscosity ny Prandtl number Pr Thermal diffusivity a The calculated properties are displayed in a scrollable view. The user just needs to scroll down to see all the results. See the screenshots below for details. If the user switches from one input variable combination to another the previously given or calculated values will be assigned to the new input values and the output is being calculated automatically. For example, if the user calculates a certain state point from pressure p and temperature t and switches to a calculation from pressure p and specific entropy s afterwards, the previously calculated value for s (from p and t) will be assigned as input value for s. This eases the calculation of thermodynamic processes in which one property is kept constant, e. g. of an isentropic expansion. The user can choose SI or I-P unit systems. In addition a variety of other units are available, e.g. K, °C, °F, °R for Temperature, MPa, bar, psi, atm for pressure, kg, lb for mass, kJ, Btu, ft lbf, kcal for energy. All units can be selected independently but the user might also switch between SI and IP unit system for all properties with just one tap. See the screenshots below this text for details. Unit conversions will be effective immediately. A detailed User's Guide explains the features and capabilities of this App. View the User's guide online on www.thermodynamics-zittau.de.