  With the increase of the elderly and disabled in the world, the
characteristics of pedestrian flow mixed with wheelchair users has being paid
more and more attention. In this study, experiments in funnel-shaped
bottlenecks were performed to study the impact of bottleneck shape and the
ratio of wheelchair users on the crowd dynamics. It is found that the increase
of wheelchairs in the crowd obviously leads to worse moving efficiency and
congestion from the escape time, time-space relationship and time headway.
Under low mixing ratios (<2.35%), less congestion occurred in the 45{\deg}
bottleneck among the four tested angles (0{\deg}, 15{\deg}, 30{\deg},
45{\deg}). The average speeds of wheelchair users is the fastest in 45 {\deg}
bottleneck (0.310m/s) until the mixing ratio arrives at 7.05%. However, the
advantage of the angle disappears when the mixing ratio gets higher. The
findings in this study is meaningful for the guidance of pedestrian evacuation
through bottlenecks with the presence of wheelchair users.
