Examples

This page provides practical examples of using sandlersteam for common thermodynamic calculations.

Basic Property Calculations

Example 1: Single State Point

Calculate properties of superheated steam at 350 C and 2.0 MPa:

from sandlersteam import State

# Initialize and resolve state
state = State(T=350, P=2.0)

# Display results
print(f"State conditions:")
print(f"  T = {state.T}")
print(f"  P = {state.P}")
print(f"\nCalculated properties:")
print(f"  v = {state.v:.6f}")
print(f"  h = {state.h:.2f}")
print(f"  s = {state.s:.4f}")

Example 2: Saturated State

Calculate properties of saturated steam at 0.5 MPa:

from sandlersteam import State

# Initialize and resolve state
state = State(P=0.5, x=1.0)  # x=1.0 for saturated vapor

# Display results
print(f"Saturated steam at P = {state.P}:")
print(f"  T = {state.T}")
print(f"  v = {state.v:.6f}")
print(f"  h = {state.h:.2f}")
print(f"  s = {state.s:.4f}")

Property Changes

Example 3: Isothermal Compression

Calculate property changes during isothermal compression:

import numpy as np
from sandlersteam import State

state1 = State(T=300, P=1.0)
state2 = State(T=300, P=10.0)
deltas = state1.delta(state2)

print(f"Isothermal Compression of Superheated Steam at T = {state1.T}")
print(f"P: {state1.P} to {state2.P}\n")
print(f"State Changes:")
print(f"  v: {state1.v:.6f} → {state2.v:.6f}\n")
print(f"Property Changes:")
print(f"  Δh  = {deltas['h']:.2f}")
print(f"  Δs  = {deltas['s']:.4f}")
print(f"  Δu  = {deltas['u']:.4f}")
print(f"  ΔPv = {deltas['Pv']:.4f}")

If we assume reversibility, we can also calculate the work done during compression:

Q = state1.T * deltas['s']  # Heat transfer
W = deltas['h'] - Q        # Work done
print(f"\nWork done during isothermal compression: {W:.2f}")

Example 4: Isentropic Expansion

Calculate work and property changes during isentropic expansion:

from sandlersteam import State

state1 = State(T=500, P=10.0)
s_target = state1.s  # Isentropic process
state2 = State(s=s_target, P=1.0)
deltas = state1.delta(state2)

print(f"Isentropic Expansion of Superheated Steam from P = {state1.P} to {state2.P}\n")
print(f"State Changes:")
print(f"  T: {state1.T} → {state2.T}")
print(f"  v: {state1.v:.6f} → {state2.v:.6f}\n")
print(f"Property Changes:")
print(f"  Δh  = {deltas['h']:.2f}")
print(f"  Δs  = {deltas['s']:.4f} (should be 0 for isentropic)")
print(f"  Δu  = {deltas['u']:.4f}")
print(f"  ΔPv = {deltas['Pv']:.4f}")

W = deltas['h']  # Work done by the system
print(f"\nWork delivered during isentropic expansion: {W:.2f}")