Thoughts on horizontal axis thruster mounting angle

The two thrusters on my ROV will be mounted at the rear of the WTE with the propeller thrust axis 10" apart. I am considering offsetting the axis of each thruster about 30 degree outward, vice parallel to the longitudinal axis of the WTE, in order to get better yawing action with decreased forward/reverse motion, when using a single thruster. I envision many cases for the intended use of my ROV where being able to achieve the desired rotation with a single thruster will save a lot of battery power. The obvious downside is decreased forward thrust, but the upside is increased angular torque when using a single thruster. When I want to rotate the ROV without forward motion I will use both thrusters (one fwd, one rev), but when some forward motion is allowable during the rotation, I can use just one thruster effectively. If I don’t angle the thrusters out, then using a single thruster for rotation will cause a lot of forward motion. I think it boils down to simple trig: a loss of roughly 15% forward thrust, but a gain of 50% (less what is already there from being mounted off the centerline axis) perpendicular thrust. Am I thinking correctly on this? I could do the math but I figure some of you can intuitively deduce this out.



Wow, too many words. I should have just asked the question: why mount the thrusters at an angle to the WTE longitudinal axis?


I presently have my four T100 Thrusters mounted at 45 degrees to the ROV Chassis longitudinal axis.

The theory here is that with this configuration the ROV Chassis can be made to move laterally right or left and stay in the same vertical plane. Also the Chassis can Yaw right or left about the vertical center of the chassis because one set of Thrusters can push forward while the opposite set of Thrusters can push in reverse.


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