Sharif Digital Repository

In this paper, the effects of water addition to a solid rocket motor (SRM) with an end-burning grain configuration are investigated, numerically. Inviscid quasi one-dimensional conservation equations are discretisked and solved using upwind Roe's scheme together with appropriate boundary conditions. The set of assumptions made to solve the problem are described in detail and the results are presented for several water inlet diameters and pressures. It is shown that, the penetration of a certain volume of water into combustion chamber can result in an ISP increase of up to 14% and therefore a performance enhancement with no extra mass of propellant  

Water resources limitation in arid and semi arid regions on one hand and water demand increase on the other, have made the optimum utilization of existing water resources and systems necessary. In this context, researchers are trying to increase the accuracy and lag time of prediction by using various statistic and empirical models as well as different local and long-range variables in the last decades. Karoon River is the greatest and most important river in Iran because of agricultural water demand supply and hydroelectric power production. Therefore streamflow prediction of this river has considerable economical and social benefits. In this study the relationship between Karoon stramflow... 

Bathymetric mapping for an accurate estimation of stored water volume in drying lakes is a key information for an effective monitoring of their recession or restoration status. Extraction of bathymetry in shallow saline lakes using remote sensing techniques has always been challenging due to the complex influences imposed by the physical properties of substrate and the spatial variability of salinity. In this study, we developed a machine learning-based model to quantify the implicit, non-linear relationship between water depth and surface reflectance by leveraging extensive in-situ data and high-resolution satellite imagery. We trained and tested the learning model in the hyper-saline Lake...