Thank you for kind reply. I also tried to make similar Rijke tube. Pyrex glass tube with 40 mm ID and 480 mm long was used. Heater was used as same one from hair dryer of 500 W. Figures are photos of heater, one is inside of tube and the other is that of outside. I tried to control the power using slidac transformer. However I could not hear any sound from the tube. I can generate sound with metal mesh and gas torch with same tube. I don't know what is wrong.