Justification of hydrodynamic loads perceived by the device for forming four-packet beams during its operation

Delivery of wood raw materials to consumers from the most remote forest areas, where its main reserves are concentrated, is often economically justified only when carried out by waterways. When branched river networks are used effectively, the initial relatively short part of the delivery route usually passes through shallow water areas. After overcoming them, it is economically feasible to enlarge timber transport units. The device discussed in the article, together with logging equipment, allows for the enlarge of timber transport units in an efficient and environmentally friendly manner. With its help, smallsized packages without compromising their integrity are assembled into two-tier, fourpacket bundles. Operating the device involves moving it from place to place. The described study is aimed at obtaining reliable information about the hydrodynamic loads acting on the device in operating condition. Their presence will ensure its reliable fastening, while avoiding excessive costs. Factors have been identified that theoretically influence the magnitude of these loads. The relationship between the hydrodynamic load and the determining factors is reduced to dimensionless form. The admissibility of excluding the Reynolds number from the number of determining factors is substantiated. Dimensionless geometric factors characterizing the shape of the underwater part of the device and the base timber transport unit are fixed. As a result of theoretical studies, an analytical formula was established by which the hydrodynamic load perceived by the device should be determined, and the dependence of the hydrodynamic resistance coefficient on the Froude number and the relative depth at the place of work was obtained, presented in symbolic form. Using this dependence, experimental studies were carried out on a physical model in compliance with similarity using a full factorial design. Based on the results of the experiments, regression models were obtained to calculate the values of the hydrodynamic resistance coefficient in the case under consideration. Knowing this value allows one to determine, using the mentioned analytical formula, the hydrodynamic load on the device with the timber transport unit located in it. An analysis of the influence of the main determining factors on the value of the coefficient under study was carried out.

1. Chekalkin K.A. Dvizheniye tverdykh tel v zhidkosti [Movement of solids in liquids]. L.: LTA, 1981. 48 p. (In Russ.)

2. Kleinstreuer С. Modern Fluid Dynamics. Springer Netherlands, 2010. 622 p.

3. Korpachyov V.P., Ryabokon' Iu.I. Soprotivleniye vody dvizheniyu lesotransportnykh yedinits v vodnom potoke: uchebnoye posobiye [Resistance of water to the movement of timber transport units in a water flow]. Krasnoyarsk: STI, 1978. 62 p. (In Russ.)

4. Pizhurin А.А. Osnovy nauchnykh issledovanij v derevoobrabotke [Basics of scientific research in woodworking]. M.: MGUL, 2005. 305 p. (In Russ.)

5. Posypanov S.V., Peskov I.A. Tekhnologiya navigatsionnoy splotki dvukh”yarusnykh paketnykh lesotransportnykh yedinits [Technology of navigational joining of two-tier packages for transport of timbers]. Alleya Nauki: [nauch.-prakt. elektr. zhurnal], 2018, no. 5-8(21), pp. 73–75. (In Russ.)

6. Rodionov P.M. Metod podobija i yego primeneniye k resheniyu zadach lesosplava [Similarity method and its application to solve timber rafting problems]. L.: LTA, 1982. 84 p. (In Russ.)

7. Voytkunskiy Ya.I., Fadeev Iu.I., Fedjaevskij K.K. Gidromekhanika [Hydromechanics]. L.: Sudostroyeniye, 1982. 568 p. (In Russ.)

8. Voytkunskiy Ya.I. Soprotivleniye dvizheniyu sudov [Resistance to ship traffic]. L.: Sudostroyeniye, 1988. 288 p. (In Russ.)

9. Weisberg S. Applied Linear Regression: Third edition. Hoboken, New Jersey: John Wiley & Sons, 2005. 329 p.

10. Xaritonov V.Ya., Posy`panov S.V. Opy`t vnedreniya edinogo transportnogo paketa vmesto molevogo lesosplava [Experience of introducing transport package instead of drift floating]. IVUZ. Lesnoj zhurnal, 2007, no. 1, pp. 45–52. (In Russ.).