I was just curious as to how you would make a glider glide in a circular pattern ( or helical ).
Will there be a large difference when considering a conventional glider vs a delta wing glider?
Assuming there is no wind, a circular pattern is most easily achieved by flying a constant speed and a constant bank angle. Maintain coordinated flight (no skidding, no slipping). There is no difference in turn dynamics between a conventional glider vs a delta wing glider.
A conventional 360 turn can be flown the same way in a powered airplane and glider: a gentle bank towards the turn, using rudder to maintain coordinated flight.
However, the purpose of a glider circling is often to catch a thermal (i.e. lifting air). In order to maximize the lifting force, a glider pilot might keep the wings level and use rudder to turn, a technique that is unique to gliders.
Delta gliders have a unique way of turning amazingly similar to the wing warping technique attempted in the early days of flight, using DRAG differential to yaw the aircraft.
This is the result of the differential of sweep angle with a change in relative wind, between the inside and outside wing. Elevons are used to roll the plane to its bank angle. The resultant sideways motion creates more drag on the inside wing, more than the "adverse yaw" created by the elevon deflection. The plane will turn without a rudder. Examples of rudderless deltas include hang gliders (weight shift) and flying wings (elevons).
Straight winged gliders do not create sufficient yaw drag differential when rolled, in fact, the ailerons will tend to yaw it in the opposite direction, hence the need for rudder input.
Conceptually, the rudder is the inside wing for a delta, and the tail for a straight winged aircraft, with many possibilities, including spoilers, in between, depending on your design style.
The large trailing portion of the delta also contributes to the turn.