In this work, a stirring and heating test system was built. An experiment at different rotational speeds within 1 h has been done for three working fluids: water, 46# hydraulic oil and saturated NaCl. Under the ideal state without considering the energy loss, the results show that the temperature rise of the working medium is faster as the rotation speed increases, the higher the heating efficiency. For example, the 46# hydraulic oil with smaller specific heat capacity is stirred at a speed of 500 r/min for 1 h, and the temperature is increased by 27.5 °C. In the same rotational speeds, the change of temperature and heating efficiency of different working fluids is complicated, and the physical parameters, such as the mass density, the specific heat capacity and the kinematic viscosity, have a great influence on the heating efficiency.

This paper presents the first report on surge extension with steam injection through both experimental and numerical simulation. The experimental section covers the test facility, instrumentation, and prestall modes comparison with and without steam injection. It is found that surge extension is not in proportion to injected steam. There exists an upper bound above which deteriorates the margin. Injection of less than 1% of the designed mass flow can bring about over 10% margin improvement. Test results also indicated that steam injection not only damps out prestall waves, but also changes prestall modes and traveling direction. At 90% speed, injection changed the prestall mode from spike to modal, while at 80% speed line, it made the forward traveling wave become backward. Through numerical simulation, location and number of injectors, molecular weight, and temperature of injected gas are modified to explore their influences on surge margin. Similar to the test results, there exists an upper bound for the amount of steam injected. The flow field investigation indicates that this bound is caused by the early trigger of flow collapse due to the injected steam which is similar to the tip leakage flow spillage caused spike stall in axial compressors.

When the working stratum pressure of the subsurface safety valve is large, the fluid in the well will have a greater impact on the valve plate, and even directly determine the opening resistance of the subsurface safety valve plate. By fluid analysis, we can get the fluid pressure cloud diagram and the velocity distribution cloud diagram of the valve plate at different opening angles, also we can get the opening resistance of the valve plate under the effect of the fluid, as well as the relationship between the resistance torque of the fluid resistance around the valve plate pinhole and the opening angle of the valve plate, providing certain guidance for the opening operation of the subsurface safety valve. Through the one-way fluid-solid coupling analysis, the stress cloud diagram and the maximum equivalent stress change under the effect of the fluid load are obtained when the valve plate is opened at different angles.

This paper introduces the wind tunnel tests and test results of two kinds of propeller with different blade angle. The 3D test section of NF-3 wind-tunnel of Northwestern Polytechnical University is used to perform the wind-tunnel test. In the test, wind speed are 0m/s, 20m/s, 30m/s and 40m/s, propeller speed are 900,