Optimizing number of fins in a heat sink

I like to make a program to optimise the heat sink design, like analysing the thermal distribution of the heat sink using different forced convection boundary condition. Please find the .STL file in the below link.

https://drive.google.com/file/d/1Q2wDoqF-Ehna88nf2NmbxsMZBd_vhsvr/view?usp=sharing

%% Model Setup for Heat Sink

clc

close all

clear all

thermalmodel = createpde('thermal','transient');

gm = importGeometry(thermalmodel,'heatsinkv2.STL');

pdegplot(thermalmodel,'FaceLabel','on','FaceAlpha',0.5);

axis equal

%% mesh

generateMesh(thermalmodel);

figure;

pdeplot3D(thermalmodel);

%% Boundary Condition, Aluminium Alloy Properties and Initial Conditions

TCval = @(location,state)139.3 + 0.204*(state.u-273.15); %sets thermal conductivity (W/m/°C) as a function of temperature only approximate equation based on linear trend for table data from ansys engineering alumnium alloy data

MDval = 2770; %Mass density kg/m^3

SHval = 875; %specific heat (J/kg/°C)

ATval = 25+273.15; %ambient temperature

CCval = 30; %convective film coefficient W/m^2

REval = 0.77; %radiation emissivity

thermalmodel.StefanBoltzmannConstant = 5.670373E-8;

faces = [1,3:30];

thermalProperties(thermalmodel,'ThermalConductivity',TCval,'MassDensity',MDval,'SpecificHeat',SHval);

thermalBC(thermalmodel,'Face',faces,'ConvectionCoefficient',@(region,state)CCval,'Emissivity',@(region,state)REval,'AmbientTemperature',ATval);

thermalBC(thermalmodel,'Face',2,'ConvectionCoefficient',5,'Emissivity',0.1,'AmbientTemperature',ATval);

thermalIC(thermalmodel,60+273.15); %sets initial temperature °C problem with this as temp doesnt go down very fast?

%% solve

tlist= [0:10]; %time from 0 to 10seconds

thermalTransientResults = solve(thermalmodel,tlist);

pdeplot3D(thermalmodel,'ColorMapData',thermalTransientResults.Temperature(:,10)-273.15)