Progress of Rain Erosion for IR Windows and Domes

A review of high velocity rain impacting and test facilities is given.Stress propagation,damage pattern and fracture mechanisms for drop impacting which is a unique surface loading are summarized.The factors influencing damage,as well as the metrics for rain erosion resistance are discussed.It is pointed out that rain erosion is a major cause of strength and transmission loss in infrared-transmitting windows and domes.Recent investigation results show that rain erosion protective coatings can improve the damage threshold velocity and durability without affecting transparency of the uncoated component.It is anticipated that there is a wide future prospects for researching durable coatings.