Mathematical modelling of airflow in shipping systems: model development and testing.

Author(s) : SMALE N. J.

Type of monograph: Thesis


This thesis is presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Palmerston North, New Zealand. Horticultural exports are of economic significance to New Zealand. Only through providing consistently high quality products to distant markets can New Zealand hope to command a premium price. New Zealand's two major horticultural exports, apples and kiwifruit, are transported to foreign markets by sea; either in refrigerated holds on-board cargo vessels or in refrigerated containers. Long transit times mean that conditions in these systems must be carefully controlled to ensure high quality product arrives at market. Effective distribution of air is a key consideration in transport systems. The model described was based on a resistance network framework, relying on simplification of the complex geometry within the refrigerated space to a discrete number of flow paths and points of convergence and divergence. Correlations quantifying the flow resistance of each channel were required. Some of these correlations were already available, and some were developed specifically for this purpose. A general method for predicting the flow resistance of enclosed conduits based on the Darcy-Weisbach, laminar and Colebrook equations was found to be sufficiently accurate for use. The flow resistance of horizontally vented horticultural packages was quantified and the cause of the flow resistance investigated. Entrance and exit effects were found to be significant, and a relationship between vent size and flow resistance was developed. Extract from the table of contents: background (shipping systems and the transport environment; measurement methods; modelling techniques; measurement method development (development of a thermistor anemometry system; further development of an in-package velocity profile determination technique); model development (flow resistance correlations; air interchange); model validation and scenario testing (refrigerated vessel).


  • Original title: Mathematical modelling of airflow in shipping systems: model development and testing.
  • Record ID : 2010-0338
  • Languages: English
  • Publication: Massey university - New zealand/New zealand
  • Publication date: 2004
  • Source: Source: 278 p. + CD-ROM; fig.; photogr.; tabl.; ref.; append.