Simulation of non-stationary gas dynamics of solid propellant rockets launch

The article presents the results of the development of methodology for the calculation of non-stationary gas dynamics processes occurring in gas dynamic paths of rocket engines and environment at the launch of rockets. The method takes into account the change of geometry of solid fuel combustion surface during the operation of the engine and the change in the geometry of the computational domain taking into account the dynamics of rocket launch. Numerical simulation of gas-dynamic processes of the launch of model solid-fuel rocket was done. The unsteady gas-dynamic flow pattern was investigated. The pressure curve in the solid propellant rocket engine combustion chamber, the speed of movement and overload were determined

Method of gas flows calculation in solid propellant rocket engines taking into account the combustion of solid fuel charge

The paper presents a method for calculating the local and integral characteristics of the flow in the axisymmetric gas-dynamic paths of solid propellant rocket motors, taking into account the combustion of a charge of solid fuel. The numerical method of calculation is based on the use of the Godunov scheme, formulated for moving computational grids. The speed of movement of the combustion surface is defined locally on the edge of each calculation boundary cell. This approach allows us to take into account the uneven distribution of the pressure of the combustion products in the free volume of the combustion chamber. In test calculations, the power law of burning rate is used. Calculations of the gas flow in the solid propellant combustion chamber with cylindrical charge of solid fuel are carried out. Unsteady pressure curve in the combustion chamber is obtained. The method allows to determine all integral characteristics of the developed solid propellant rocket motors as a function of the engine running tim

IDENTIFICATION OF IMMUNOGENIC PROTEINS OF STRAINS OF BACILLUS ANTHRACIS IN MALDI TOF MS

Aim. Identification of obtained in host-simulated conditions immunogenic proteins of isogenic variants of Bacillus anthracis 575/122. Materials and methods. We used culture filtrate of isogenic variants of B. anthracis 575/122: R02 (pXOL pXO2+); R01 (pXO1+ pXO2‘); R00 (pXOL pX02~), obtained in host-simulated conditions. In the one-dimensional polyacrylamide gel electrophoresis and immunoblotting with hyperimmune serums immunodominant proteins, that have been identified in MALDI TOF MS. Results. Immunoblotting revealed proteins with molecular masses in range 97 - 14.1 kDa. 90 kDa protein from strain B. anthracis 575/122 R01 in MALDI TOF MS was identified as protective antigen with 85.810 kDa. Protein with molecular mass 60 kDa was identified as GMP synthase with molecular mass 57.239 kDa. In the culture filtrates of three strains two common antigen were identified: protein with molecular mass 97 kDa, identified as B. anthracis EA 1 with molecular mass 91.361 kDa protein and 45 kDa protein as enolase B. anthracis with molecular mass 46.418 kDa. Conclusion. Thus, the conditions that simulate the host can promote the production of immunodominant proteins of B. anthracis. The data about molecular-weight characteristics of protective antigen and EA 1 protein as well as some of proteases of B. anthracis are confirmed by the MALDI TOF MS. The results can be used for isolation of these proteins to improve the diagnostic and vaccine preparations