جستجوی مقالات مرتبط با کلیدواژه "شرایط بهینه" در نشریات گروه "مکانیک"

The usage of biodiesel quality monitoring system (online and batch) is always the basic requirement of its production which requires to research in this area. The purpose of this study is to predict and optimize the palm biodiesel characteristics using its permittivity properties. The parameters of biodiesel permittivity properties (ε’, dielectric constant and ε″, loss factor) at microwave frequencies of (434, 915 and 2450 MHz) were used as input variables. The palm biodiesel characteristics as fatty acid methyl ester (FAME) content and flash point (FP) at three different level of reaction time (3, 9 and 27 min) and catalyst concentration (1, 1.5 and 2 % w/woil) were selected as output parameters for the models. The response surface methodology was developed for prediction and optimization of FAME content and flash point. The optimum condition was obtained using RSM by FAME content of 95.87% and flash point of 162.7 °C with desirability of 0.999.

In the present study, the heat transfer, moisture distribution, air flow and thermal comfort in a residual room which is warmed by convectional thermal panels under different environmental conditions was assessed numerically. The analyzed model is the real and dynamic 3D simulation, and a virtual thermal manikin with real physiological dimensions has been added to the model. The manikin is standing at the center of room. The room has dimensions of 3*4*4 m with an inlet device that has dimensions of 1.28*0.054 2 m and two outlet devices with dimensions of 0.054*1.02 2 m . The inlet and outlet devices have been modeled above and under the door. To determine the optimal arrangement and number of panels, three models have been studied. The models include one panel with real dimensions of 1.242*0.81 2 m , two panels with real dimensions 0.61*0.962 m and three panels with real dimensions 0.61*0.81 2 m , with a thickness of 20cm in all panels. The uniform distribution of temperature, velocity and moisture, and proper and symmetric arrangement of panels, inlets and outlets decrease the energy consumption and satisfy the thermal comfort of inhabitants. Thermal loss increases due to the panels under the window. It was concluded that using two panels with smaller dimensions at the left and right of the model instead of one panel under the window or three panels at the left, right and under the window significantly reduces the thermal loss.