Numerical and experimental investigation of plasma plume deflection with MHD flow control

This paper presents a composite magneto hydrodynamics（MHD） method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.

Experimental investigation on plasma jet deflection with magnetic fluid control based on PIV measurement

This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector effect.Magnesium oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.

Robustness analysis and distributed control of a networked system with time-varying delays

This paper is concerned with the robustness analysis and distributed output feedback control of a networked system with uncertain time-varying communication delays.This system consists of a collection of linear time-invariant subsystems that are spatially interconnected via an arbitrary directed network.Using a dissipation inequality that incorporates dynamic hard lQCs(integral quadratic constraints)for the delay uncertainties,we derive some sufficient robustness conditions in the form of coupled linear matrix inequalities,in which the couplld parts reflect the interconnection structure of the system.We then provide a procedure to construct a distributed controller to ensure the robust stability of the closed-loop system and to achieve a prescribed lzgain performance.The effectiveness of the proposed approach is demonstrated by some numerical examples.

Experimental study on plasma jet deflection and energy extraction with MHD control

This paper presents an integrated research scheme for vector deflection and energy extraction in a gas plasma jet under Magneto-Hydrodynamic(MHD)control.A MHDcontrolled thrust-vector test rig was used to conduct the experimental research.A gas plasma was obtained by injecting ionization seeds of Cs2CO3 into the combustion chamber via artificially forced ionization.The effects of the gas temperature and ionization seed mass fraction on the plasma jet deflection and energy extraction were experimentally verified under an applied magnetic field.The experimental results were analyzed theoretically.The results showed that the deflection amplitude of the gas plasma jet and the extracted voltage signal intensity increased with increasing gas temperature and the ionization seed mass fraction.The extracted dynamic voltage signals proved that the ionization seeds of Cs2CO3 induced gas ionization at 1173 K.The experiment verified that it is feasible to simultaneously achieve jet deflection and extract energy under the action of an external magnetic field.

Probe design for measuring total temperature of combustor outlet based on water cooling

To obtain the outlet temperature of combustor,a kind of high-temperature and water cooling thermocouple was designed.The main factors affecting the results of thermocouple measurement were analyzed after numerical simulation.Results showed that the high-temperature water cooling thermocouple can achieve high temperature measurement under the condition of 2 400 K.With the increase of the distance between the water cooling structure and the stagnation cover,the temperature measurement result was more accurate,and the increase in the area ratio of the inlet and outlet of the stagnation cover within a reasonable range can make the measurement results more accurate.The surface emissivity of the measuring point had a great influence on the radiation error.The pressure and flow rate of cooling water can be effectively reduced after adding zirconia coating onto the surface of the rake body.

Experiment of gas plasma plume deflection by magnetic control

To investigate the deflection effect of gas plasma plume controlled by magnetic field,a novel experimental scheme was presented.The Cs2CO3 catalytic ionization seeds were injected into the combustion chamber to obtain gas plasma on a high temperature magneto hydrodynamic(MHD)experiment rig.The plasma jet was deflected under the action of an external magnetic field,resulting in a thrust-vector effect.Particle image velocimetry(PIV)collected two-dimensional images of jet flow field.Through image processing and velocity vector analysis,the jet deflection angle can be obtained quantitatively.At 1800-2500 K,the jet deflection was verified experimentally under the condition of 0.45 T magnetic field strength.The results indicate that the jet deflection angle increases gradually with the increase of gas temperature,and above 2200 K,the jet deflection angle increase obviously.In the process of gas plasma jet,it is feasible to realize the jet deflection controlled by MHD by adding an external magnetic field.