NTU_FROM_P_BASIC

This function computes side-1 transfer units from side-1 temperature effectiveness and heat-capacity ratio for basic exchanger configurations. It supports analytical and numerical inversions depending on subtype.

The solved quantity is \mathrm{NTU}_1 = f^{-1}(P_1, R_1, \text{subtype}).

Excel Usage

=NTU_FROM_P_BASIC(p_one, r_one, basic_subtype)

p_one (float, required): Thermal effectiveness with respect to stream 1 (-).
r_one (float, required): Heat capacity ratio with respect to stream 1 (-).
basic_subtype (str, optional, default: “crossflow”): Basic exchanger subtype (-).

Returns (float): Thermal number of transfer units with respect to stream 1 (-).

Example 1: NTU for counterflow basic exchanger

Inputs:

p_one	r_one	basic_subtype
0.975	0.1	counterflow

Excel formula:

=NTU_FROM_P_BASIC(0.975, 0.1, "counterflow")

Expected output:

3.98477

Example 2: NTU for parallel flow basic exchanger

Inputs:

p_one	r_one	basic_subtype
0.55	0.5	parallel

Excel formula:

=NTU_FROM_P_BASIC(0.55, 0.5, "parallel")

Expected output:

1.16198

Example 3: NTU for crossflow basic exchanger

Inputs:

p_one	r_one	basic_subtype
0.85	0.7	crossflow

Excel formula:

=NTU_FROM_P_BASIC(0.85, 0.7, "crossflow")

Expected output:

5.20718

Example 4: NTU for crossflow mixed fluids

Inputs:

p_one	r_one	basic_subtype
0.65	0.3	crossflow, mixed 1&2

Excel formula:

=NTU_FROM_P_BASIC(0.65, 0.3, "crossflow, mixed 1&2")

Expected output:

1.29197

Python Code

Show Code

from ht.hx import NTU_from_P_basic as hx_NTU_from_P_basic

def NTU_from_P_basic(p_one, r_one, basic_subtype='crossflow'):
    """
    Solve NTU for a basic exchanger from effectiveness and capacity ratio.

    See: https://ht.readthedocs.io/en/latest/ht.hx.html

    This example function is provided as-is without any representation of accuracy.

    Args:
        p_one (float): Thermal effectiveness with respect to stream 1 (-).
        r_one (float): Heat capacity ratio with respect to stream 1 (-).
        basic_subtype (str, optional): Basic exchanger subtype (-). Valid options: Counterflow, Parallel, Crossflow, Crossflow Approximate, Crossflow Mixed 1, Crossflow Mixed 2, Crossflow Mixed 1&2. Default is 'crossflow'.

    Returns:
        float: Thermal number of transfer units with respect to stream 1 (-).
    """
    try:
        result = hx_NTU_from_P_basic(P1=p_one, R1=r_one, subtype=basic_subtype)
        return result
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

p_one *

Thermal effectiveness with respect to stream 1 (-).

r_one *

Heat capacity ratio with respect to stream 1 (-).

basic_subtype

Basic exchanger subtype (-).