So I am looking to possibly use a ring transducer that has a hoop vibration mode to power a sonoluminescence experiment I am doing for school. I am attaching a picture of the set-up I have now and the aluminum disc in the picture is where I will epoxy the transducer so it can send sound waves into the water. My question is, if I lay lay a piezoelectric ring transducer on a flat aluminum disc and epoxy it, since it is in hoop mode which to me means that it will be having mechanical movement perpendicular to the direction of the water, will any sound energy be transferred to the water? Please help me I am very lost in my research right now. Thank you!