Q dT AT0

where Q is the heat transferred per unit across a surface A, dT/dL the temperature gradient with respect to thickness L at the surface A, and k the thermal conductivity expressed as the amount of heat transferred per unit time through a unit area of surface for 1° temperature difference over a unit wall thickness. The negative sign indicates that temperature decreases as thickness increases.

The steady-state heat transfer through the chamber wall of a liqud-cooled rocket chamber can be treated as a series type, steady-state heat transfer problem with a large temperature gradient across the gaseous film on the inside of the chamber wall, a temperature drop across the wall, and, in cases of cooled chambers, a third temperature drop across the film of the moving cooling fluid. It is a combination of convection at the boundaries of the flowing fluids and conduction through the chamber walls. The problem is basically one of heat and mass transport associated with conduction through a wall. It is shown schematically in Fig. 8-20.

The general steady-state heat transfer equations for regeneratively cooled thrust chambers can be expressed as follows:

where q is heat transferred per unit area per unit time, Tg the absolute chamber gas temperature, 7} the absolute coolant liquid temperature, Tw/ the absolute wall temperature on the liquid side of the wall, Twg the absolute wall temperature on the gas side of the wall, h the overall film coefficient, hg the gas film coefficient, hi the coolant liquid film coefficient, tn. the thickness of the chamber wall, and k the conductivity of the wall material. The strength and thermal properties of materials are functions of temperature. Any consistent set of units

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Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

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