A simple model is presented for the Hugoniot energy change in condensed media subjected to a strong shock. Approximating the structure of the liquid by a cell model and assuming annthinsp;minus;thinsp;6pair potential, an expression is obtained for the configurational portion of the internal energy change. Changes in thermal energy and the effects of relaxation processes are ignored since the final state involved in the energy balance is selected to coincide with the state of molecules just after they have attained the particle velocity, but before significant translational relaxation has taken place. The Hugoniot energy change is then approximated by the change in configurational energy. The derived Hugoniot fits available data for five simple liquids within experimental error when a consistent and realistic value ofnis chosen. A single value of 8.5 is found to produce good agreement between experimental and predicted results for argon at initial temperatures of 86deg; and 148deg;. Values ofnfor argon and nitrogen agree closely with those found from molecular beam scattering studies.
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