Owner of a single engine aircraft reported the aircraft was damaged by the jet blast of a parked business jet.

Narrative

I am the owner of Aircraft X. On Day 0; while operating at ZZZZ; my aircraft was involved in a serious ground safety incident caused by jet blast from a large business jet.After landing and receiving normal taxi clearance from Air Traffic Control; my aircraft was taxiing on the apron behind Aircraft Y at an estimated distance of approximately 165 feet. At that time; the engines of Aircraft Y were running at a high thrust setting. The resulting jet blast lifted and destabilized my aircraft; causing it to roll and strike the ground with the propeller and wingtip. My aircraft sustained significant damage.At the time of the incident; I was not piloting Aircraft X. I was located on the same airport in another aircraft and witnessed the event directly; along with another pilot. I could hear the pilot of Aircraft X transmitting on the radio requesting that the jet engines be shut down due to the hazard; but the Control Tower advised that they had no radio contact with Aircraft Y.Following the incident; personnel on board Aircraft Y identified themselves as mechanics from a third party maintenance company. There was no pilot on board the jet at the time. The mechanics stated that they were conducting engine operations for maintenance purposes; trying to 'burn off fuel'. They gave inconsistent explanations regarding whether the engines were at idle or higher power settings (at one point 40% was mentioned) and whether they had authorization from the Tower.It later became apparent that the engines of Aircraft Y had been running on the apron for an extended period of time; reportedly close to two hours; without Tower communication and without intervention by airport authorities. The aircraft was parked in a general aviation apron area; and was surrounded by safety cones. No rotating beacon; anti collision lights; or other visual indications of engine operation were observed. Based on these indications; the aircraft appeared to be inactive and not running engines. There was no visual or radio warning that engines would be operated.This event raises serious safety concerns regarding engine operation of large jets on apron areas; lack of Tower communication; absence of a pilot in command during engine operation; and the inability of airport systems to detect or intervene in prolonged high power engine activity on the ground. The jet blast created an immediate hazard to smaller aircraft and could easily have resulted in injury or even loss of life.I am submitting this report to highlight systemic safety issues related to ground operations; maintenance engine runs; and oversight at mixed use airports where light aircraft operate in proximity to large jets.