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Nodal Analysis of Stirling Cycle Devices

Description: This paper describes a general-purpose program for the nodal analysis of Stirling-cycle devices or other cyclic regenerative machines, and presents an extensive discussion of results for an illustrative problem. The program employs finite-difference, explicit-forward solutions, and is readily adaptable to various machine topologies. The machine is divided into specifiable numbers of fluid and solid nodes. The program solves the gas-dynamic differential equations (mass, momentum and energy balances) for each fluid node and an energy balance for each solid node. Interactions between these are represented by heat transfer and fluid friction terms. The kinetic energy of the fluid and the inertial resistance to flow acceleration are accounted for. Leakages through seals and ports are included in the analysis. Special schemes for enhanced mathematical stability and for accelerated convergence to a steady-state cycle are employed. The program is applicable to both disciplined-piston and free-piston engines. It can automatically generate very detailed outputs, both tabular and graphic (Eulerian, LaGrangian, and 3-dimensional) to help provide insight and understanding. Extensive illustrations and discussions are presented. There are two copies in the file and an extra copy in the ESD files.
Date: January 1, 1978
Creator: Schock, Alfred
Partner: UNT Libraries Government Documents Department

Stirling Engine Nodal Analysis Program

Description: A general-purpose program for the nodal analysis of Stirling-cycle devices or other cyclic, regenerative machines is described. It employs finite-difference, explicit-forward solutions, and is readily adaptable to various machine topologies. The machine is divided into specifiable numbers of fluid and solid nodes. The program solves three coupled gas-dynamic differential equations (mass, momentum, and energy balances) for each fluid node, and an energy balance for each solid nod. Interactions between these are represented by heat transfer and fluid friction terms. The kinetic energy of the fluid and the inertial resistance to flow acceleration are accounted for. Leakages through seals and ports are included in the analysis. Special schemes for enhanced mathematical stability and for accelerated convergence to a steady-state cycle are described. The program is applicable to both disciplined-piston and free-piston engines. It can automatically generate very detailed outputs, both tabular and graphic (Eulerian, LaGrangian, and 3-dimensional) to help provide insight and understanding. Extensive illustrations and discussions are presented.
Date: January 1, 1978
Creator: Schock, Alfred
Partner: UNT Libraries Government Documents Department

A Thermally-Integrated Spacecraft Design Approach Using Nuclear Dynamic Power Systems

Description: The use of dynamic-cycle heat engines for space electric power systems makes it possible to design a spacecraft which is thermally integrated with the power system. The power system fluid loop is used to cool the spacecraft equipment and structure. This results in a spacecraft which is extremely insensitive to changes in sun-angle, eclipse periods, or power dissipation. Resultant temperature variations of equipment is seen to be a few degrees in the worst-case orbits, without the need for active thermal control. Organic Rankine and Brayton cycle generators are considered. Cycle power losses of less than one-percent are experienced in implementing this concept.
Date: January 1, 1978
Creator: Raab, Bernard
Partner: UNT Libraries Government Documents Department