A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or...A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or compressor effects could be simplified as body forces along the streamline. These body forces which are functions of local parameters could be added as source terms in Navier-Stokes equations to replace solid boundary conditions of blades and hubs. The val- idation of SBFM with uniform inlet and distortion inlet of compressors shows that pressure performance characteristics agree well with experimental data. A three-dimensional simulation of the integration configuration, via a blended wing body aircraft with a distributed propulsion system using the SBFM, has been completed. Lift coefficient and drag coefficient agree well with wind tunnel test results. Results show that to reach the goal of rapid integrated simulation combining internal and external flow fields, the computational fluid dynamics method based on SBFM is reasonable.展开更多
Partial surge is a type of instability inception discovered in our previous studies.It has been confirmed that partial surge is localized in the blade hub region,and the flow oscillation it caused will lead to the sta...Partial surge is a type of instability inception discovered in our previous studies.It has been confirmed that partial surge is localized in the blade hub region,and the flow oscillation it caused will lead to the stall cells in the rotor tip.While since all information about partial surge is obtained from the compressor stage experiments,what will happen to the stall process after the stators are removed is also an issue that worth investigating.So,in this paper,a series of experiments are carried out on the single rotor embedded in the transonic compressor stage with partial surge inception.First,the experimental results under uniform inlet conditions show that,although partial surge appears at high rotor speed in the stage case,it does not occur at any speed in the single rotor case.Then,it is found by numerical simulation that the absence of partial surge may be due to the insufficient rotor hub loading,so an experiment with increased hub loading is carried out,but still fails to trigger partial surge.Finally,the reason why partial surge doesn’t occur in the single rotor is discussed.From these results,it can be concluded that partial surge cannot occur in the single rotor case,and the large-scale comer separation in the stator hub is considered to play an important role in the formation of partial surge.展开更多
基金supported by the National Natural Science Foundation of China (No.51176005)
文摘A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or compressor effects could be simplified as body forces along the streamline. These body forces which are functions of local parameters could be added as source terms in Navier-Stokes equations to replace solid boundary conditions of blades and hubs. The val- idation of SBFM with uniform inlet and distortion inlet of compressors shows that pressure performance characteristics agree well with experimental data. A three-dimensional simulation of the integration configuration, via a blended wing body aircraft with a distributed propulsion system using the SBFM, has been completed. Lift coefficient and drag coefficient agree well with wind tunnel test results. Results show that to reach the goal of rapid integrated simulation combining internal and external flow fields, the computational fluid dynamics method based on SBFM is reasonable.
基金This study is financially supported by National Natural Science Foundation of China(Grant Nos.51636001 and 51976005)National Science and Technology Major Project(Grant No.2017-II-0005-0018).
文摘Partial surge is a type of instability inception discovered in our previous studies.It has been confirmed that partial surge is localized in the blade hub region,and the flow oscillation it caused will lead to the stall cells in the rotor tip.While since all information about partial surge is obtained from the compressor stage experiments,what will happen to the stall process after the stators are removed is also an issue that worth investigating.So,in this paper,a series of experiments are carried out on the single rotor embedded in the transonic compressor stage with partial surge inception.First,the experimental results under uniform inlet conditions show that,although partial surge appears at high rotor speed in the stage case,it does not occur at any speed in the single rotor case.Then,it is found by numerical simulation that the absence of partial surge may be due to the insufficient rotor hub loading,so an experiment with increased hub loading is carried out,but still fails to trigger partial surge.Finally,the reason why partial surge doesn’t occur in the single rotor is discussed.From these results,it can be concluded that partial surge cannot occur in the single rotor case,and the large-scale comer separation in the stator hub is considered to play an important role in the formation of partial surge.
