Experimental study on NOxemission characteristics of a valveless self-excited pulse combustor of Helmholtz type with bend tailpipes was carried out.The results show that

when the combustor's structure is fixed

the NOxemission at tailpipe exit increased first and then decreased with the increasing heat load

it decreased with an increase in excess air ratio.The combustion temperature and residence time of the flue gas in high temperature area has great influence on NOxemission of the Helmhotlz pulse combustor.Generally

there is a reasonable heat load window in which the NOxemission becomes low due to short residence time of the flue gas in high temperature zone

although heat load and combustion temperature are very high.