How to apply a variable direction pressure

Hello everyone, I'm using Hypermesh 2017 and I have a project where simulate the load of a belt on a pulley alog a wrap angle opf 111°, the pulley has trapezoidal groove(polyV type with 40°angle. In this simulation i made a semplified model that is a simple disk with a single trapezoidal groove.

For my analysis I have to apply two loads:

-a normal pressure wich vary along the arc of load: I succed to do with equa

The pressure should vary along an arc of contact of 111° with equation 76484*exp(y*0.32838), selecting the local coordinate cilindrical system, I give the two side of the trapezoidal grive as faces (I selected only that of the arc)

The tangential load along the arc of contact: I 'd like to do in the same manner but I cannot give a tangential direction along the arc of contact.

The only option for the direction is x-axis, y-axis, z-axis, vector and N1 N2 N3.

I tried all the possibilty:The y-direction is relative to the global system and there is not possibilty to specify that is relative to the local cylindircal system (it seems that the system is only relative to the equation), with the vector i can specfy a tangentail vecotr (that I make aside) but the dircetion don't vary. 

There is a solution to make this?

I also try with the force laod and this works but the problem is tahta I wnat a pressure and not a force otherwise I have to calculate How many nodes/mm2 there are to make the calculation of the right force load to give

Normal Pressure load (succeded)

Tangential load (not succede): this are the option for the direction

This is the load that I give but is a force load applied to the nodes (also if I select the faces in the same manner) in this case the direction is relative to the local system (cylindrical sistem selceted), why this doesn't work for the pressure?

Maybe this is solved in successive version of the program?

Thank you for the help