Effects of Fluids on Mechanical Properties and Performance

As the next step, an analysis of the consequences of jets should be performed. The following effects of jets on targets should be taken into account mechanical load (pressure, impact), thermal load (temperature, including thermal stresses and shocks where appropriate) and properties of fluids (such as possible short circuits in electric equipment due to the conductivity of liquid water). Possible chemical effects should also be taken into account, especially if the fluid ejected is other than water. It may be... 

The first decision in the design of a rubber formulation is the selection of the base polymer to be used. This choice will be determined principally by the end-product specification and/or service conditions. This will stipulate such conditions as upper and lower operating temperatures, type and level of chemical or fluid resistance, mechanical or electrical properties, etc. This task requires a comparison of the basic properties of the polymer types and grades available with a view to making a selection on a cost-effective basis. There are few areas of ambiguity about the choice of polymer to be used as most polymers have a specific profile of chemical and physical properties. Where a single polymer cannot provide the requisite properties, then a blend of two or more may often be used. The performance aspects of the polymer are discussed further in Section 7.5. 

The interaction between the biological system and these materials is very complex and strongly influenced by fluid mechanics. The designer should carefully consider surface modification of any of these materials. Surface modification can be performed, including ion implantation or grafting of various substances to the surface, to promote improved compatibility but delamination or flaking has occurred. Manufacturing and fabrication processes have a profound effect on the properties of these materials and must be carefully analyzed and controlled. 

---