Open pressure-adjustable submerged jetting water tunnel and flow field forming method thereof

An open pressure-adjustable submerged jetting water tunnel comprises a working water tank. The working water tank comprises a top pressure adjustment cavity. In the working water tank, the space below the pressure adjustment cavity is divided into a test area and a pressure adjustment section. The lower part of the pressure adjustment cavity is communicated with the test area and the pressure adjustment section. The sidewall of the test area is connected with an upstream water source through a flow channel. The flow channel directly faces a test object installed in the test area, and the flow channel is equipped with a velocity adjustment valve. The pressure adjustment section is beyond the working water tank downward, and extends downward to form a pressure adjustment vertical shaft which is communicated with a downstream water pool. The test area and the pressure adjustment vertical shaft are each provided with a lifting overflow dam. The pressure adjustment cavity is provided with a pressure adjustment sys