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1.
Model studies of the hydraulic operating conditions of an eddy tunnel outlet with an inclined shaft showed that:
–  for regimes without delivery of air into the flow core with swirler parameterA=1.1 and with delivery of air for all values ofA, submergence of the outlet section of the conduit in the lower pool noticeably affects the size of the core and promotes the formation of a hydraulic jump zone along the tunnel;
–  insignificant (in value) submergences of the exit section of the tunnel have little effect on the discharge capacity of the outlet (their differences is Δ=1.4% forA=0.6, Δ=2.71% forA=1.1, and submergence even increases the discharge of the outlet Δ=0.8% forA=0.83).
–  delivery of air into the flow core has little effect on the discharge capacity of the structure, with the exception of the layout with a swirler withA=0.6 (Δ=4.31% forA=0.6, Δ=0.5%, and Δ=0.9% forA=1.1);
–  considerable vacuums are observed for regimes without air in the flow core, the absolute values of which with increase ofA drop intensely from Hfc=−4.5 m to Hfc=−0.3m;
–  delivery of air into the flow core markedly reduces the vacuums in it and their values are close to zero;
–  with increase of swirler parameterA the area occupied by the flow at the end of the tunnel decreases;
–  regimes without delivery of air into the flow core are the most favorable with respect to the conditions of the pressure distribution on the conduit walls;
–  submergence on the downstream side does not lead to an increase of pressure on the conduit walls if the vacuum in the flow core increases simultaneously with this.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 41–44, November, 1997.  相似文献   

2.
1.  Investigations showed that when constructing dams of fine-grained silty soils by hydraulic filling, it is expedient to use the technology of layerwise placement of soil with consolidation of each layer.
2.  Dependences are given for calculating the thickness of the layers and period of consolidation of the soil on the basis of investigations of the dynamics of the hydrophysical properties of these soils in relation to technological factors.
3.  Dependences are also proposed for predicting the density of the hydraulic-filled soil during construction, as well as the distribution of soil in the profile of the structure.
4.  A method is proposed for calculating the technological parameters, in particular, the rate of construction of hydraulic-fill structures, calculating the size and number of the hydraulic-fill plots referred to one dredge, and prediction of the seepage discharge into the foundation of the dams during their hydraulic filling.
5.  The proposed calculation methods make possible a more substantiated approach to the design of hydraulic-fill structures of fine-grained silty soils and technology of their construction.
Translated from Gidrotekhicheskoe Stroitel'stvo, No. 6, pp. 5–9, June, 1990.  相似文献   

3.
1.  The designs as well as the total safety factor of concrete-encased steel pressure conduits of operating hydraulic structures were analyzed.
2.  The principles of the existing standards related to calculations of concrete-encased steel pressure conduits were analyzed.
3.  Methods of calculating concrete-encased steel pressure conduits (including forks and distributors), including elements of the inside steel shell and reinforced-concrete part, were developed.
4.  The calculation methods developed were experimental substantiated and tested during designing and constructing domestic and foreign objects.
Translated from Gidrotekhnicheskoe Stroitel'stvo No. 1, pp. 37–44, January, 1999  相似文献   

4.
1.  The energy-storage hydroelectric station (ESHES) can provide a 1.5–2-fold increase in peak capacity with a simultaneous threefold decrease in daily fluctuations of the water level in the lower pool.
2.  A decrease in the length of the concrete structures located in the river channel (especially the length) of the powerhouse) reduces the consumption of concrete for the ESHES in comparison with the HES, which compensates for the cost of constructing the additional structures of the ESHES.
3.  Unlike the HES, the ESHES operates in a sharp-peak regime and also during passage of flood waters.
4.  Contrarotating pump-turbines are best suited for an ESHES because of various combinations of heads on its turbine and pump parts.
5.  With increase in the speed of multistage hydraulic machines their placement depth decreases and the cost of the powerhouse is reduced.
  相似文献   

5.
1.  The hydraulic characteristics of cohesive mudflows in the case of a hydraulic jump, other conditions being equal, differ considerably from those for a pure water flow.
2.  The scheme of calculating a hydraulic jump of a cohesive mudflow requires taking into account, along with the hydrostatic pressure, also the pressure caused by cohesive forces and angle of internal friction of the mudflow mixture.
3.  The change in the ratio of the depth H2/H1 before and after the jump completely depends on the kinetics parameter of the mudflow, values of cohesion and angle of internal friction.
4.  Several subcritical depths, determined by the concentration of the mudflow mixture and physical and mechanical properties of the medium, correspond to the jump function of a cohesive mudflow.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 45–47, December, 1991.  相似文献   

6.
1.  A comparison of laboratory and on-site data on a determination of the maximum range of oscillations at the end of a direct hydraulic jump when waves enter it from a chute with the results of calculations by theoretical formulas (1), (2), and (3) confirms the applicability of one of these formulas (2) for superrapid flow and flow transitional from superrapid to rapid.
2.  The stilling basin generates secondary waves, reaching half of the depth of the basin d with respect to its height. With submergence of the basin from the lower pool, the range of variations of the level increases additionally by 2.0–2.5 times.
3.  On the apron behind the stilling basin, the drop of waves is insignificant, since the wave transformation coefficient at distance (40–90)hn, where hn is the natural depth, remains equal to .
4.  The periods and lengths of the waves transformed in the stilling basin decrease with increase of discharge and Froude number Fr0 and approach in value the wave periods.
5.  Formulas (6) and (10) were obtained for calculating the maximum amplitude of oscillations of the free surface and maximum depth at the crest of oblique waves on the narrowing sections of the wave chutes and they were checked experimentally, which proved the applicability of these formulas for calculating a nonstationary oblique hydraulic jump.
6.  The proposed empirical formulas (12)–(17) can be recommended for an approximate evaluation of the parameters of the largest first waves on the narrowing stretch.
7.  Under these conditions, the use of a stilling basin as an energy dissipator of a superrapid flow is not rational, since not dissipation but generation of secondary waves is observed in it. When designing narrowing sections of chutes, it is necessary to take into account an increase of depth of the oblique jump with passage of roll waves.  相似文献   

7.
1.  As a result of the investigations, the distribution of the discharge and current velocities in braided channels of a flatland river under natural conditions and with the implementation of various engineering measures was obtained. The effective measures on regulating the distribution of discharges in a braided channel for activating dying channels were determined.
2.  The regularities of fluid flow at the point of separation were established, which have a substantial effect on the results of calculating the distribution of the discharge in the channels. Detailing of the calculations of the distribution of the discharge in channels by means of the main equation of uniform motion without consideration of the regularities of fluid motion at the point of separation leads to an increase of the deviation of the results obtained from the actual data.
3.  The results of the investigations have importance for developing optimal variants of structures being designed and increasing the reliability of existing structures, for improving the navigation conditions on rivers with an analogous scheme of braiding of the flow, since they reflect the characteristics of the distribution of discharges and velocities in a braided channel under various conditions which are not being taken into account by the existing hydraulic calculation methods.
Translated fromGidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 27–29, February, 1989.  相似文献   

8.
1.  The plant manufacturer's power and efficiency guarantees are fulfilled.
2.  The power performance curves obtained for the hydraulic unit at four heads make it possible to select the makeup of operating units that will deliver maximum economy with the load distributed between the units.
3.  In operating the hydraulic units, special attention should be given to adjustment of the combiner curves in connection with the fact that its mismatch downgrades not only the economy of the hydraulic-turbine operation, but also the vibrational state of the hydraulic unit.
4.  Measurements of the vibration levels of the hydraulic units under several heads made it possible to determine the boundary line with respect to power over the entire range of operating heads.
Translated from Gidrotechnicheskoe Stroitel'stvo, No. 4, pp. 26–30, April, 1991.  相似文献   

9.
1.  An intake structure with a closed flow having a vertical axis of rotation contributes to the development of a favorable kinematic structure in the channel, which makes it possible to minimize scouring beyond the structure.
2.  Excedence of the near-bottom average and maximum velocities above the average velocities in the channel comes about atl3.3hc downstream from the axis of the intake.
3.  The magnitude of the ratio of the maximum 1st-percentile and average 50th-percentile flow velocities (v1%/v50%), which characterizes the velocity pulsation, attains values for the undisturbed flow in the near-bottom region at a distancel4.1hc.
4.  Complete equalization of the plan diagram of velocities is noted at a distance (4.9–7.8)hc from the axis of the intake structure.
Translated from Gidrotechnicheskoe Stroitel'stvo, No. 4, pp. 17–19, April, 1991.  相似文献   

10.
1.  In designing constricting chutes, for example, the configurations and heights of the sides, it is necessary to study cases of possible nonuniform flow in the inlet section of the chute, which develop as a result of violation of the rational scheme of gate maneuvering.
2.  The effect of the configuration of the chute sides may make itself felt appreciably on the extinguishment of flow energy.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 31–34, November, 1990.  相似文献   

11.
1.  When ventilating complex underground hydraulic systems during their construction it is necessary to take into account the natural draft.
2.  The method presented for calculating the natural draft pressure drop of single tunnels (formulas 1–6) reflects the specific characteristics of hydrotechnical construction in mountainous areas and for the first time takes into account the direction of movement of the ventilation flow.
3.  For the particular conditions of constructing the Rogun hydrostation the values of the lapse rates were established, which can be used in calculations to take into account the natural draft when designing the ventilation of underground workings.
4.  For calculating the natural draft pressure drop of a complex network of underground workings, an algorithm was developed which makes it possible to calculate by a standard program on a computer the air distribution in the underground complex being constructed in relation to a number of technological and natural factors.
5.  On the basis of analyzing the results of different variants of the air distribution, the selection of the types and arrangement of the ejector fans (including in the future) was optimized, making it possible to increase the quality of ventilation and safety of underground operations, as well as to obtain a substantial technical-economic effect.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 26–29, August, 1988.  相似文献   

12.
1.  Sludge storage ponds can be located on any foundation soils, but economic calculations should be made for selecting the site.
2.  In the presence of seismic conditions, it is necessary to remove weak soils within the shoulder in order to provide its stability with a steepness of the downstream slope up to m=5. Other methods providing stability of the shoulder can also be used with appropriate technical and economic substantiation.
3.  The stability and possible liquefaction of soils of the shoulder should be determined only according to the guide Consideration of seismic loads when designing hydraulic structures, which is the only standard with respect to this problem.
4.  The size of the hydraulic-fill beach is determined on the basis of the particle-size distribution of the slurry.
5.  The permissible minimum width of the hydraulic-fill beach is determined on the basis of calculating the stability of the shoulder.
6.  It is necessary to recommend the construction of a siphon intake (discharge) located on the bank of the settling pool, which gives a more reliable and economical solution.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 53–55, December, 1991.  相似文献   

13.
1.  One of the new approaches to the use of wave power plants can be their use as a source of compressed air for operating a pneumatic breakwater.
2.  The use of wave power plants for protecting marine hydraulic structures from the effect of storm loads makes it possible to increase the cost effectiveness both of the WPPs themselves and of the hydraulic structures.
3.  A rough estimate of the cost of wave power plants shows their effectiveness as a source of electrical energy for remote regions of the USSR.
4.  The simplicity of the design of wave power plants enables organizing their mass production at shipyards or at the site of construction.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 7–10, February, 1992.  相似文献   

14.
1.  In certain cases of constructing dams salt-containing soils serve as their foundation.
2.  Under these conditions reliable operation of the structures can be provided only by developing special engineering measures to control dissolution.
3.  All existing methods of protecting saliferous foundation soils of hydraulic structures from dissolution can be divided into passive, active, and combined.
4.  The combined methods should be considered the most effective for preventing removal of salts from foundation soils by the seepage flow.
5.  Large-scale field investigations of the work of the combined method of protecting saliferous foundation soils of the planned Lower Kafirnigan hydro development showed its high effectiveness even in the case of complex engineering-geological conditions at the construction site.
6.  Individual elements of the set of dissolution protective measures investigated under field conditions can be used in hydrotechnical and hydropower construction practice.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 10–14, October, 1994.  相似文献   

15.
An analysis of the experience in the Soviet Union and in foreign countries with conveyor transportation in the mining industry, as well as with use of conveyors in hydraulic construction shows that the introduction of conveyor transportation in the field of construction of embankment dams in this country, for delivery of earth-rock material from quarries, as well as for carrying raw materials to concentrating plants processing nonmetallic minerals, will make it possible.
1)  To reduce substantially the personnel nees.
2)  To lower significantly the transportation costs for delivery of earth-rock materials to construction sites and to concentrating plants processing nonmetallic mateirals (rubble, gravel, and sand);
3)  To reduce the need for trucks, by replacing them with conveyors;
4)  To increase the rate of delivery of earth-rock materials from quarries for dam, construction and, consequently, to reduce the times of completion.
5)  To reduce the volume of housing, cultural-welfare, and auxiliary-subsidiary construction in owing to the lower needs for personnel in conveyor transportation;
6)  To eliminate the need for constructing a large number of roads with rigid pavements for large-capacity dump trucks;
7)  To raise the technical level of the earth-rock work.
  相似文献   

16.
Conclusions  
1.  The expediency of hydraulic-fill grading of marshy coastal territories and city dumps for housing construction and recreation park and beach zones was proved practically.
2.  Underwater coastal borrow pits in the shallow-water zone can be used for direct dredging of soil.
3.  In the absence of sand borrow pits, fine-grained loamy sand soils can be used for hydraulic filling the construction sites.
4.  To operate dredges on large water areas under conditions of violent wind-wave action, it is necessary to work out a special works organization plan taking into account the preservation of supply lines, machines, and crew during a storm and under ice conditions in the winter.
5.  The possibility of using the ash of heat and power plants for engineering grading of a marshy territory for housing construction on a pile foundation was proved.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 9, pp. 29–33, September, 1997.  相似文献   

17.
Conclusions  
1.  The systems of elongated triangles located at elevations 413, 467, and 344 m do not give reliable results, as a consequence of which they cannot be used as horizontal displacement meters.
2.  The displacements of the ends of the adits recorded from the NET readings are a consequence of measurement errors.
3.  The use of string systems as horizontal displacement meters of hydraulic structures can be used only with their complete protection from airflows, which is practically impossible to do.
4.  The use of 3-m invar bars, used as meters of the small sides of the NET, for determining deformations of concrete and bank adits is possible.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 52–54, September, 1998.  相似文献   

18.
1.  The operating regime of the MFPT has a determining effect on the value and direction of action of radial forces.
2.  The presence of radial seals on runners does not lead to an unequivocal decrease of radial forces on the rotor.
3.  The use in MFPT of radial seals of the runner with the geometric parameters used in the usual turbines is accompanied by considerable RFs on the rotor, greater than in the turbines.
4.  A decrease of radial forces simultaneously in the PR and TR will cause difficulties in connection with differences in the values of the optimal parameters of the seals for each of the given regimes.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 22–25, December, 1994.  相似文献   

19.
1.  Aerated water jets are finding wide use in solving a number of practical problems. A determination of the effect of braking of the velocity field in a jet as a function of the air content is especially important.
2.  On the basis of laboratory experimentation, a formula (8) of the decrease of the relative axial longitudinal velocities in water-air jets spreading beneath the water level as a function of the air content in their initial section is derived.
3.  The length of the initial section of a jet changes considerably in the presence of aeration and can be determined by formula (9).
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 22–24, July, 1990.  相似文献   

20.
1.  The hydraulic projects awarded prizes by the Council of Ministers of the USSR in 1976 solve a set of critical national-economic problems and are distinguished by high cost effectiveness.
2.  Structures distinguished by originality and progressiveness of technical solutions, which ensure their reliable operation, have been constructed as the result of a set of scientific-research and design studies. This was made possible only by the close creative understanding and interaction between the scientific-research, planning, construction, and operating organizations.
3.  In building hydraulic structures, all the more attention is focused on industrial aesthetics. The architectural-planning solutions of the prizewinning projects are new, represent examples of the progressive development of industrial architecture, and have obtained widespread public recognition.
4.  The bold and economic solutions relative to the organization of the passage of flood waters over incomplete structures merit attention; this makes it possible to reduce the volumes of the enclosing foundation pits of the cofferdams, or eliminate them entirely.
5.  The experience gained with the design and construction of the prizewinning projects should be studied in detail and publicized for purposes of utilization in subsequent design and construction.
  相似文献   

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