What design pattern to use for generating multiple simulations?

I have a simulation that runs at a specific height and a specific temperature:

interface ISimulation
{
    string Name { get; }
    int Height { get; }
    int Temperature { get; }
    void Generate();
}

The Generate() process for a simulation typically involves multiple steps:

void Generate()
{
    GenerateStep1();
    GenerateStep2();
    GenerateStep3();
}

Now, it is possible for the user to specify multiple heights and/or multiple temperatures.

In this case, multiple simulations (sub-simulations) are spawned off, one per each height/temperatue combination.

interface IMultiSimulation
{
    string Name { get; }
    int[] Heights { get; }
    int[] Temperatures { get; }
    void Generate();
}

In this case however, the Generate() of the sub-simulation would have to change as follows:

• If multiple temperatures are specified, then GenerateStep2() needs to be performed only once for all sub-simulations, and not per temperature.
• If multiple heights are specified, then:
  • GenerateStep1() is performed first on all sub-simulations.
  • Step2 and Step3 are then performed.
• It is possible to have a grand simulation with multiple heights AND multiple temperatures. This means that 2 above criteria need to be satisfied.

I've been trying to use the decorator pattern but with no success. What are some tips I could use to handle the complexity of my code?

Thanks.