I'm going to cast my vote with NE Wisc's suggestion of Aristolochia but let me offer some caveats and observations. I used to work a couple hundred miles north of you in Minnesota and western Wisconsin so I'm familiar with the region. While there I worked with Humulus (hops), Clematis spp., Actinidia (hardy kiwi), Parthenocissus (Virginia Creeper), Vitis (grapes), Wisteria macrostachys & W. frutescens, Campsis radicans (Trumpet vine), Lonicera x brownii (Honeysuckle), and Akebia. For many of these if I never encounter them again it will be fine with me. Most vines, given favorable growing conditions, have decidely imperialistic ambitions.
Aristolochia is fast growing and will produce a nearly opaque screen but in moderate shade (where many vines are decidedly unhappy) it is not excessively aggressive. The big plus from my perspective, and as has been noted, is that it is the preferred food source for the caterpillars of Battus philenor the Pipevine Swallowtail butterfly. How do you feel about caterpillars munching on your vines? The biggest downsides of Dutchman's Pipe are that the flowers aren't very showy (usually hidden in the foliage) and it doesn't produce any significant fall color.
Virginia Creeper, by contrast, is a very showy red in the fall but it is also much more of a thug than Dutchman's Pipe in my experience. Don't plant it unless you are game for a fight.
Clematis ternifolia, , Sweet-autumn Clematis, is very showy when in bloom in late summer/early fall. I have only grown it in nearly full sun so I really don't know how it responds in part shade. In warmer climates it is considered an invasive exotic but the cold winters in Ames should restrain its imperial ambitions.
I do not think you will find Passion Flower to be hardy in Iowa.
Wisteria macrostachys 'Aunt Dee' is the hardiest Wisteria in my experience but it really prefers full sun. Wisteria futescens 'Amethyst Falls' was slightly less hardy but might be okay for you. Again it really prefers full sun.