A significant part of the experimental investigations (EI) in wind tunnels (WT) aimed at simultaneous measurement of air pressure at distributed points as in the WT, and aircraft models (AM) and in jet engines. In this regard, the actual problem is creati
Journal Title: Інформаційні системи, механіка та керування - Year 2015, Vol 0, Issue 12
Abstract
A significant part of the experimental investigations (EI) in wind tunnels (WT) aimed at simultaneous measurement of air pressure at distributed points as in the WT, and aircraft models (AM) and in jet engines. In this regard, the actual problem is creation of means and methods for simultaneous measurement of pressure as discussed in the work. The first method. The holes of the selection pressure pneumatic tracks (PT) are connected to the pressure sensor (PS), which are connected to the channels of the measuring system (MS). In this MS apply precision instrumentation programmable filter, communication interface with computer and time measurement for channel ≤40ms. The cost of this MS is high, even for 16 channels measurement interval ≥640ms, which for most of the EI is not acceptable. The second method is the use of electro-mechanical pneumatic switches (EMPS). For example, in EMPS type PS-180/ 300/ 420 continuously rotating the rotor of the switching node with a phase shift connects PT to PS, synchronously with the time of establishment of pressure measurement is performed. The third method is the use of mobile pneumatic modules with interface for the transmission of real-time experimental data (ED) in MS. Such devices, for example, can be up to 16 with the number of measured channels and 256. The proposed unified information-MS (IMS), which can be implemented on different hardware and software platforms (VME, PC/104, MicroPC, etc.). Processing. Is calculated, sorted and stored value of the absolute and relative pressure pulsations of velocity head. Determine the mean value and standard error. Normal distribution was confirmed by ED Pearson criterion at the significance level . Statistical reproducibility of ED is confirmed by the criterion of Cochran, assess the homogeneity and error. Is determined by the Reynolds number based on the physical parameters in the WT. The accuracy of the ED algorithm provides operational control of IMS. The transformation function PS is defined in terms of the polynomial. In difficult cases it is necessary to use D-optimal plans experiment. The coefficients of longitudinal and normal components of aerodynamic force, the coefficient of longitudinal moment, the relative position of the center of pressure, normal and tangential components of aerodynamic forces. The problem is to compute the integral with minimum error. It is recommended to apply the Romberg method.
Authors and Affiliations
Валерій Петрович , Зінченко, Сергій Валерійович Зінченко, Ли Вей
Keywords
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