Encyclopaedia Index


The River-Oil-Spill Analyser

rosa What is ROSA?

ROSA is a special purpose interface to the PHOENICS CFD code.

It is an integrated software package for simulating the development of oil slicks and other spillages.

It has been validated against a number of hydraulic models and full scale river spillages, especially in Siberia where environmental concerns have become a major issue.

All the relevant physical phenomena (wind strength and direction, temperature, etc.) are taken into account.

The applicability of ROSA
When oil (or other chemicals/pollutants) is spilled into a river we would wish to:
  • predict water quality in terms of pollutant concentration over time and space
  • in the short-term, predict slick movements and formulate an emergency response
  • in the long-term, predict deposition of pollutant and formulate a management and clean-up strategy

Modelling features of ROSA
ROSA comprises the following modules linked by a menu system:

  • The river-current sub-models
  • The oil-spill sub-models
  • The data-entry module
  • The visualisation module

Oil pollutants within the river are considered as consisting of:

  • A surface slick floating on the water surface
  • A mixed layer containing suspended oil fragments
  • There is continuous exchange between the two layers and mass losses to the atmosphere
  • The surface layer thickness is much less than that of the suspended layer which is equal to the flow depth

ROSA Validation
ROSA has been validated against a number of reliable laboratory and field measurements of velocity field and free surface elevations in two and three dimensions for open channels and river courses.

Free-surface flows in open channels
A number of free-surface flows have been simulated and validated against experimental data, including:

  • flow in open turnaround channel,
  • abrupt open channel expansion,
  • flow impingement on bluff body,
  • merging of streams,
  • flows in channels with complex bed shapes and
  • meandering open channel flows.

Good agreement has been achieved both for free surface elevation and velocity distributions.

Other capabilities

  • ROSA is a modelling tool capable of simulating movement of oil and other pollutants on the surface of rivers, which flow at a constant rate.
  • It has recently been extended, adding the capability to simulate flows that vary with time, i.e. tidal flows.
  • This enables ROSA to be used to simulate the movement of oil in estuaries, along coastlines and on the open sea, greatly enhancing the usefulness of ROSA as a tool for predicting the spread of oil slicks.
  • A further ROSA capability is the ability to simulate the movement of ice flows on oceans.


Applications Library
ROSA Lecture

For further information about ROSA, licence arrangements, consultancy, seminars and courses, and more specifically what it can do for you, contact CHAM.

Concentration, Heat & Momentum Ltd
Bakery House, 40 High Street
Wimbledon Village, London SW19 5AU
United Kingdom
Tel: +44 208 947 7651
Fax: +44 208 879 3497

Copyright 1999 CHAM Ltd.