## Blog Archives

## Applied Research

## THE INFLUENCE OF INITIAL PRESSURE ON THE CHARACTERISTICS OF DETONATION WAVES IN BUBBLE LIQUIDS

Detonation waves exist in a variety of environments. Despite the differences in the structure and physical-chemical properties of systems detonation wave in all environments share common characteristics: detonation – a self-sustaining process. This fact is a manifestation common to all systems, properties are chemically active environment. It is the presence of energy in the environment provides the possibility of the existence of waves of detonation.

Detonation in bubble media is a unique phenomenon: a bubble detonation wave can exist in systems with extremely low energy content, mass the caloric content of chemically active bubble system by six orders of magnitude smaller than conventional solid or liquid explosives. The detonation in bubble environments, possessing common to all of the detonation wave characteristics, has a number of features, manifested in the structure, properties and mechanism of spreading [1-7].

Detonation – dissipative process: the possibility of propagation of detonation waves is provided by the energy deposition in the environment. In bubble media type» chemically inactive liquid–gas bubbles chemically active «substance capable of energy release are in the gas phase (gas bubbles). If you change the initial pressure with a given volume concentration of the gas phase mass concentration of gas and therefore the energy content of the system change. Thus, the initial pressure of the bubble environment is an important parameter affecting characteristics and the possibility of existence of detonation waves.

The study of detonation waves in bubbly liquids related to the issues of explosion safety of such systems. From experiments [7] it is known that the initial pressure significantly affects the speed and amplitude of waves of bubble detonation. Therefore, it is necessary to study the influence of initial pressure in the bubble on the system characteristics (speed, amplitude, amplitude and length of the original signal capable to initiate a blast wave in a bubbly liquid) detonation waves.

## THE CALCULATION OF THE COEFFICIENTS OF THE LANGMUIR EQUATION FOR THE FORMATION OF A DATA BANK ON THE ISOTHERMS OF ADSORPTION

Problems of design of the adsorptive installations with adsorbers of periodic action with a stationary layer of adsorbent are considered. The method of calculation of coefficients of isotherms of adsorption of Lengmyur by minimization of not knittings of skilled and settlement data on condition of uncertainty of borders of area of optimization is stated. A basis of calculation is set of a method of the smallest squares and a method of scanning of a fragment of area of a research of a two-parametrical task with consecutive search of about extreme area and its research with the decreasing steps. The calculated coefficients of the equation of Lengmyur as the databank element on isotherms of adsorption which is a fragment of the computer-aided engineering system of the adsorptive installations are provided. On examples good convergence of results of calculations of isotherms of adsorption with experimental data is shown. The block scheme of the computer-aided engineering system of adsorbers with a stationary layer of adsorbent allowing to carry out calculation of the device for various characteristic areas of isotherms of adsorption, and also to fill up a databank with information on new systems an adsorbate adsorbent is provided.

The algorithm for calculating coefficients of the equation of Langmuir adsorption isotherms in uncertainty optimization allows to develop a computer-aided design of adsorption units. Shows the block diagram of the systems of the automated designing adsorbers periodic action with a stationary layer of adsorbent.

## METHOD FOR INCREASING SPEED AND REDUCING THE ERROR OF MULTIDIMENSIONAL PRECISE LOGIC CONTROLLER

A novel technique has been suggested for increasing multidimensional precise logic controller (MPLC) speed of action based on arrangement of production rules in situation subprograms, initial points of which are registered in special register by fuzzification procedure according to equality to the logical unit of the control parameters precise terms. It enabled to process but one subprogram selected during fuzzification rather than the entire system of the controller production rules without damaging control adequacy in each scanning cycle.

According to their logical nature, each situation subprogram is a software implementation of a production rule, which must be executed when one of the precise terms of each MPLC controlled parameter is equal to a logical unit. The correct assignment of MPLC controlled output variables ranges the microprocessor executes one rule for each multidimensional precise logic controller loop. And to find this rule, the standard procedure for applying to the subprogram is used, which is now well minimized by microprocessor time and storage. It should be noted that in the standard multivariate fuzzy logic controllers the entire system is executed, comprising out of tens or even hundreds of production rules in similar situations in each loop, which leads to a significant decrease in performance.

Two fundamental properties (at any given instant both only one term and only an antecedent of one rule is equal to a logical unit) of precise terms set and production rules systems under consideration are the theoretical basis for improving MPLC speed and reducing its error.

## ANALYTICAL MODEL OF TEMPERATURE AFTER FLOW RATECHANGE

At present time the interest to the quantitative interpretation of temperature surveys is growing. Individual flow rate and reservoir pressure of each layer, behind-casing flow rate, hydrodynamic layer parameters, characterization of permeability changing at near-wellbore zone become the purposes of quantitative interpretation. Non-stationary temperature and pressure in the well are used as input data for transient processes analysis, and temperature logs are used for quasi-stationary analysis. Particular interest is in determination of the individual layer flow rates and near-wellbore zone parameters.

The paper studies the problem of unsteady temperature field in heterogeneous reservoir during fluid filtration. The aim of this work was to develop and provide rationale for simplified analytical model of non-isothermal single-phase fluid filtration in heterogeneous reservoir. Analytical solution for the temperature field in the formation after flow rate changeis obtained by the method of characteristics. Two assumptions were made in solving the problem: radial thermal conduction and compressibility of saturated porous medium are ignored. Analytical models are compared with the numerical solution of the problem. Radial heat conduction and compressibility of oil- or water-saturated reservoirs influence insignificantly on the unsteady temperature field after the flow rate changes.

It is possible to solve the inverse problem on the evaluation of the damage zone radius of the permeability in the reservoir basing on the model curves of the temperature change after flow rate change. The possibility of that method realization is demonstrated on model curves of the temperature change.

## THE INFLUENCE OF DIFFERENT FACTORS ON THE FLAME TEMPERATURE OF THE FLARE UNIT

The article considers the problem of estimation of flame temperature and the study on it the main parameters of a flare. In the typical company in accordance with the terms of reference were designed flare unit designed for burning waste gas in one of the fields of the Russian Federation.

Evaluation of the temperature in the flame front of gas were discharged from the following considerations.

From theory it is known that during the combustion of unmixed gases the flame front is established in those locations where suitable in the combustion zone the flow of reagents (discharged gas and air) are in stoichiometric ratio. The temperature in the flame front is maximized. In this model the combustion process, the temperature of the flame front can be determined from the heat balance equation. The temperature of the flame front , which is an argument in all the components of the right side of the equation, you can determine in deciding this non-linear relative to the temperature equation one way or another. In this paper, for finding temperature was used numerical method for solving nonlinear equations by the method of half division (dichotomy). The paper presents original data and a sample calculation of the temperature-designed flare. The calculation of the effect on the flame temperature of the flare unit of the following factors: flow rate of discharged gas, the diameter of the tip the flare, temperature of discharged gas, combustion efficiency, net calorific value of natural gases and the excess air ratio. The results of this work are engineering methods and a computer program for calculating the temperature used in the analysis of variants of the designed construction of a flare.