The introductory part of the work contains brief information about the existing peristaltic pumps and their application areas. Special attention is paid to the use of miniature peristaltic pumps with a linear located tube. For such pumps, there is a sufficient number of experimental studies, but a very limited number of studies are devoted to modeling the flow in such pumps. The aim of the work is to develop a technique for calculating the characteristics of a peristaltic pump with a linear located tube and several squeezing elements that not completely compress it in the transverse direction, , based on a quasi-stationary model and verifying the applicability of the developed model by numerical modeling. A quasistationary model is obtained by compiling the Bernoulli equation for the instantaneous velocities and pressures for the current movements of the squeeze element. To evaluate the limitations of the applicability of the quasi-stationary model, numerical experiments were performed in the STAR-CCM + program taking into account the possibility of cavitation, for which the Eulerian polyphase model was used. Numerical experiments have shown that cavitation takes place at intervals when the pump discharge member returns to its initial position and the pressure in the compression area decreases. From a comparison of calculations with different pump cycle times, it is established that cavitation is essential only if the squeeze elements move too fast and the pump cycle time is sufficiently short. It was also found that fluctuations in fluid velocity within the pump are observed under the same conditions as cavitation. Comparison of the results of numerical simulation and calculations using a quasi-stationary model has shown that the calculations give an error in the time intervals when there is a simultaneous movement of pump squeeze elements. As a result of the analysis of the obtained results, it is concluded that the developed quasi-stationary model can be used for calculations if the viscosity of the pumped liquid is not less than 40 mPa •s and if the pump operating frequency is sufficiently small that the pump does not experience the specified cavitation and speed fluctuations.

Peristaltic pumps are used in a wide variety of applications due to their tightness, ease of mainte-nance and accurate delivery. Nevertheless, the use of peristaltic pumps is limited by their disad-vantages: short service life of the working body and uneven feed. This work provides an overview of the existing design solutions for pumps. The main advantages and disadvantages of the most common modern designs of peristaltic pumps are considered. The developed design solutions are presented. These solutions are designed to extend the service life of the elastic working body of the pump. These include a spiral hose design, where hose life is improved by reducing the number of cyclic compressions using just one roller. Another solution is to operate the pump with incomplete compression of the working element, which reduces the stress values and thereby prolongs the ser-vice life of the working element. The special shapes of protrusions in the compression area were developed in order to compensate the decrease in flow caused by the operation of the pump with incomplete compression of the working member. The paper provides an overview of solutions to reduce the uneven flow of a peristaltic pump. The simplest of these is the use of multiple parallel channels. In other designs, the elimination of flow pulsations is achieved with a pneumatic damper. There is also a constructive solution, in which a special algorithm of actuation of five squeeze ele-ments is used for uniform supply, each of which compresses only its own section of the pump working body. Based on the analysis, it is shown that in order to eliminate the disadvantages of per-istaltic pumps the various methods are used. Nevertheless, those methods need further improve-ment.

In the overview part of the work, the most common existing designs of pumps of the peristaltic principle of operation, as well as the main areas of their application, are briefly presented. The main part of the work is devoted to the study of the influence on the operation of a peristaltic pump with a linearly arranged tube of the shape of the cross-section of the tube in the region of the compressible sections, as well as the ratio of the sizes of the release elements periodically compressing the pump tube in the transverse direction. The studies were carried out through numerical experiments in the STAR-CCM + program, which is based on the control volume method. As a result of the carried out calculations, it was found that the use of protrusions on the inner surface of the tube gives a positive effect if the protrusions have a special curvilinear shape with a smooth transition near the inner surface of the tube, and the increase in the generated pressure and feed is greater if the protrusions are present only in the compression region tube with the first squeeze element. In this case, the discharge angle of the pump characteristic changes so that a positive effect is not observed in the region of small values of the generated pressure. The study of the influence of different ratios of the lengths of the compressible sections of the tube on the flow and pressure created by the pump showed that for the incomplete compression of the pump tube investigated in the work, the use of squeeze elements of the same length is favorable. Both for a tube without protrusions and for a tube with protrusions, the use of a second squeeze element of greater or lesser length than the length of the remaining squeeze elements with the same total length of all three compressible sections leads to an increase in leakage when the tube is not fully compressed, and thus reduces the pump flow.

The paper investigates the effect on the linear peristaltic pump operation of the properties of the material of its elastic tube, the algorithm of actuation of the release elements, as well as the presence of irregularities in the inlet and outlet sections of the pump in the form of alternating confusers and sudden expansions. To study the influence of these factors, a series of numerical experiments was carried out using the universal software STAR-CCM +, where the pump operation was simulated by a joint calculation of the fluid flow and elastic deformations of its tube. As a result of numerical experiments for a number of values of Poisson's ratio, it was found that the material of the pump tube must be selected with the lowest possible Poisson's ratio in order to obtain the highest efficiency. The study of possible algorithms for the actuation of the release elements of the pump showed that in order to obtain the maximum efficiency, the pump operation mode should be select-ed in accordance with the drive design. The drive, where energy is expended only on the movement of the release elements, requires the mode with the first release elements to hold the tube in a com-pressed state longer, which provides a higher feed value. For the drive, where energy is spent on maintaining the tube in a compressed state, the preferred mode is the one with the delay in the re-turn of the release element to its original state is minimal. As a result of studying the influence of sections with irregularities, it was found that the use of the height and pitch of irregularities, when the ratio of the resistances of these sections in the forward and reverse flow is optimal, leads to a decrease in the flow and pressure of pump.

The article presents a study of the tube form influence on performance of the peristaltic pump with the linearly placed tube and several pushers squeezing it in the transverse direction. The coupled numerical simulation of fluid flow and solid domain deformation was carried out using the software, based on the finite volume method. The cross sections with surface protrusions of two different types are considered for numerical simulation. The simulation results have shown that protrusions without a smooth transition at the tube walls reduce the compression ratio of the tube and therefore yield the flow rate reduce. Protrusions with s smooth transition at the tube walls on the contrary increase the flow rate in a high pressure range. Higher flow rate and pressure values achieved in the case of surface protrusions placed in the first compression region of the tube only. Comparison of pump characteristic curves shows that the use of tube surface protrusions can significantly increase the energy efficiency of the pump.