VIPER REXUS

Thermal Control

1. Thermal Tasks

 

  • The experiment requires an unusual effort of thermal calculations
  • the preparation and analysis of the ice blocks, the analysis of the heat probe and the general design of insulation and cooling

Power and Heat exchange flow chart

 

2. Heat Probe

 

  • As a key parameter the power needed to vaporize the ice and the power loss was calculated

 

3. Ice Preparation

 

It’s very important to ensure a high quality of the ice throughout the experiment for best results. Therefore a specific procedure for preparing the ice blocks is needed. The requirements of highly undercooled ice includes a homogeneous structure with no gas inclusion. Furthermore, it enables us to compare the results of our experiment to the previous calculations.
Some of our team had a few ideas and attempts of different methods to create ice blocks fulfilling the requirements, which you can see below.

1. Method:

    filtered, cool water frozen in one piece

2. Method

    • : filtered water,pre cooled in fridge, covered when cooling/freezing,

 

    frozen in one piece

3. Method

    : filtered water, pre boiled, frozen in layers, layers applied still hot

4. Method

    • : filtered water, pre boiled, covered at all times, frozen in thin layers,

 

    layers applied still hot

 

Calculating the heat transport through convection we can estimate the time, the ice blocks can possibly endure between mounting and rocket launch in order to meet the requirements.

The analysis is conducted with the following parameters:

diameter d = 0.052 m

height h = 0.065 m

density of ice ϱ = 918 kg/m^3

mass m = 0.1267 kg

temperature of environment T_air = 10 °C

end temperature of ice T_ice_end = -30 °C

Assumption: perfect insulation, no conduction

T_ice_start Prior cooling method Time Insulation
-78.5 °C Dry ice 32.5 min bottom
-78.5 °C Dry ice 190.2 min bottom, side
-196.15 °C Liquid nitrogen 60.2 min bottom
-196.15 °C Liquid nitrogen 371.8 min bottom, side

4. Insulation and Cooling

 

Considering mass and power consumption, we decided to use passive cooling combined with insulation for our experiment.

Insulation:

  • placed around the walls of the ISCA

Passive cooling:

  • possibly a cooling gel placed between the ice blocks

 

Members of this division:

    Kai Schüller

    Thermal Control (Leader), Science

    degree:              Aerospace Engineering M.Sc.
    focus:                spaceflight, numerical modelling

      Marian Friedrich

      Structure, Thermal Control

      target degree:  Aeronautical Engineering B.Eng. (8th Semester)
      focus:                propulsion technology