Air Tables Starter Kit (Excel macro-enabled tool) — Download this file for access to begin using Excel custom formulas for evaluating thermodynamic properties of the ideal gas air, modeled as having variable specific heat. Link to the PPT file for background and tips for getting started. The source data is from Moran and Shapiro textbook tables.
Pitot Probe Air Velocity Calcs
This simple file demonstrates how to calculate velocity in a duct or in the environment from a pitot probe and water manometer sensor arrangement.
Variable Cp Relationships for Ideal Gases
This Excel file tabulates fourth-order polynomial coefficients for Cp as a function of temperature for a wide selection of ideal gases. How is variable Cp used? Recall for an ideal gas: h2-h1 = Integral (Cp dT). When Cp is variable, you must integrate Cp(T)dT in order to determine the enthalpy change.
The following ideal gases have their Cp variable coefficients tabulated in this file: CO, CO2, H2, O2, N2, Air, SO2 (sulfur dioxide), CH4 (methane), C2H2 (acetylene), Ne.
Thermodynamic Properties of Air (Moran Tables)
Thermodynamic properties (h, u, so, Pr, Vr) of air with variable specific heat are tabulated in both SI and English units. Data source is Moran’s Engineering Thermodynamics textbook. Recall that air is treated as an ideal gas, and the tables model the air with variable specific heat.
This file incorporates a linear interpolation tool where the user enters any of (T, h, u, so, Pr, or Vr) and a set of Excel computations returns the property values corresponding to the specified property.
To use this tool for your own application, use Save As… to preserve the connection of the tabulated property values to the Excel interpolation computations.
Air Standard Cycles Interactive Demo
Basic air-standard cycle analyses, clearly explained, for Otto, Diesel, Dual, and Brayton cycles. Uses ideal gas model with constant specific heat. The user controls the key input parameters (like minimum and maximum temperatures and pressures) and has the ability to visualize the effects on T-s and/or P-v diagrams. Also gives ability to explore how thermal efficiency is affected by the key input parameter values.
Air Properties
Multiple-tabs for various properties of air, treating air as an ideal gas with VARIABLE SPECIFIC HEAT. Includes polynomial expression for Cp as a function of temperature. Integrals of Cp dT and Cp/T dT (for evaluating enthalpy changes and entropy changes). Includes viscosity, thermal conductivity, and Prandtl number of air as a function of temperature.
Air Compressor Calculations
Determine the power (and cost per hour) required to operate an air compressor for a desired compressed air flow (cfm).