**Turbine4_CL**

The function Turbine4_CL(n_s) uses a curve fit to the Balje curve peak to provide the optimal value of specific diameter for a turbine given the specific speed. These curves were developed in:

Sondelski, Becky, *Mass Optimization of a Supercritical CO2 Brayton Cycle with a Direct Cooled Nuclear Reactor for Space Surface Power*, M.S. Thesis, Dept. of Mechanical Engineering, UW-Madison, (2019).

and are based on the Balje curves presented in Balje, O.E., *Turbomachinery*, New York, Wiley & Sons, (1981).

The calling protocol is:

Turbine4_CL(n_s)

**Inputs:**

n_s = specific speed (rad) = omega*sqrt(V_dot)/Dh_s^0.75

**Output:**

d_s = specific diameter (-) = D*Dh_s^0.25/sqrt(V_dot)

Note that the companion function Turbine3_CL provides the efficiency as a function of specific speed and specific diameter.

**Example: **

$Load Component Library

n_s=1

d_s=**Turbine4_CL**(n_s)

eta_max=-999

eta = **Turbine3_CL**(n_s, d_s, eta_max)

{d_s = 2.34, eta = 0.6955}