A new approach to field modelling

de dk es fr it cz ru cn

RSS Twitter Facebook Linkedin YouTube

>> >> >>

ISOkorsis pipe system

ISOkorsis pipes are designed for the free-flow sewerage systems and drainage in freezing soils (with a laying the depth less than the depth of seasonal freezing and permafrost conditions) when there is a risk of the pipes freezing. In the modeled system sewage water (+10 °C) occupies 2% of the pipe's cross-section. Velocity of the sewage water is 1 m/s. Sewage freeze as a result of heat exchange with the environment. It's necessary to calculate the sewage water freezing time and the maximum allowed length of the pipe.

Problem type:
Plane problems of steady-state and transient heat transfer.


1 - insulation; 2 - outer pipe; 3 - inner pipe; 4 - sewage water.

Initial temperature of the sewage water Tsewage = 10 °C;
Sewage water velocity v = 1 m/s;
Freezing depth of the soil h = 2.5 m;
Temperature of the air Tair = -50 °C

Determine the sewage water freezing time and the maximum allowed length of the pipe to avoid the sewage freezing.

The solution consists of two stages:

  1. Initial temperature distribution in the empty tube is determined (steady-state heat transfer problem);

  2. Water is added to the pre-cooled tube. Sewage water then cools down to 0 °C. Time till the beginning of the water crystallization is calculated (transient heat transfer problem).


It takes 7 seconds to cool down water from 10 °C to 0 °C. So after 7 seconds water begins to freeze. For the given flow rate of 1 m/s the maximum length of the pipe is 7 meters. If longer pipes are needed, it is necessary to use a heating system.

Download PDF icon View simulation report in PDF.

Download Download simulation files (files may be viewed using any QuickField Edition).

There are no restrictions applied to the QuickField Student Edition postprocessors.
You can view field maps, make plots, calculate integrals and print pictures in the same way that the Professional Edition users do.