Fan Test Rig
ME 414w, Professor Yavuzkurt
Fall Semester, 2006
Ingersoll Rand has requested the design and construction of a testing apparatus for the analysis of cooling packages used in two types of pavement and soil compactors; namely the SD-100 and the DD-92 models. These models are similar to the ones shown below. This test rig will allow the company to test a variety of fan and cooling package set ups.
Noise regulations are becoming stricter in both the United States and Europe. New regulations effective in January 2006 institute a new “buy quiet” policy for European companies. This policy limits the types of equipment American companies can sell in the European Union. The limit on construction vehicle noise varies from country to country but tends to be around the 105 dB level.
In addition to noise, this test rig will be used to collect data on air velocities, pressures, fan RPM and power consumption. This additional data will allow Ingersoll Rand to evaluate a variety of effects caused by varying the cooling fan design and operating parameters, as well as balance the cooling package effectiveness versus fan noise production.
Previously, noise testing at Ingersoll Rand was done on fully assembled equipment. This is a unique project in that it will test output parameters in a system that is as close to the real thing as possible. This unit will be unlike other fan testing devices due to the fact that it is not only testing the effects of the fan impellers, but also testing the performance of the fan as a function of different operating parameters. Some of these parameters include the distance from the fan hub to the engine, fan/fan shroud interaction and fan RPM. This is a very specific testing apparatus designed solely to emulate the conditions present in the SD-100 and DD-92 compactors. This test rig will enable relatively quick and easy testing of cooling package configurations inside a mocked up engine compartment.
Due to budget restrictions for this project, a one quarter scale model of this testing rig was also designed. This test rig was the model constructed by our team during the semester. The details of each are given below.
The frame is produced from A36 structural steel and overall it measures 48 inches across by 96 inches in length. The height is 36 inches. The corner posts are 3 in. x 3 in. square tubes that each stand thirty-six inches tall. The corner posts have steel plates welded to each end, one for a foot, the other as a cap. The foot is a 5 in. x 5 in. x 0.25 in. plate welded to the bottom of the tube. The caps are made of a similar thickness plate that is cut to the size of the tube and are welded to the top. All longitudinal and cross members of the frame are made from C3 x 6 steel channels. This is a slight deviation from the originally proposed design that called for a tubular steel frame. This change was made to realize a cost savings for the sponsor. The cross members are all 36 inches long and mount to the outside of the corner posts via a welded joint. The long members are all 96 inches in length. One pair the long members mount to the outside of the corner posts with two ½-13 ASTM A490 grade structural bolts on each end. These bolts have minimum yield strength of 130,000 PSI and a minimum tensile strength of 150,000 to 170,000 psi. Each end of the inside pair of long members mount with the same type of bolts as the outside long members. These members have a plate welded to each end that supply the beam with four mounting holes on each end.
The cooling package, supplied by Ingersoll Rand, will mount using a very similar system to that used by the manufacturer. Each inside long member has a pair of eight inch long slots that will allow the location of the cooling package to be adjusted. The figure on the left shows the location of these slots. The cooling package will be supported by a pair of 3 in. x 1.5 in. x 0.250 in. steel angles that are 18 inches in length.
The mock-up engine (left) will be made of sheets of pressure treated plywood that will be held together with 1.50 in. x 1.50 in. x 0.125 in. aluminum angle. A picture for the design may be seen in Figure 5. The mock engine will have two 2 in. x 0.250 in. aluminum bars mounted underneath for support. The bars will have two 5 in. slots milled into them lengthwise that will allow the engine to be moved in the longitudinal direction on the framework. The engine will be supported on the frame by two cross members that will be made of 3 in. x 3 in. x 0.25 in. steel.
The cooling fan will be driven by a three phase, 60 Hz, 230/460 V, 20 HP, 3600 RPM, inverter duty, standard efficiency, open enclosure, 256TC frame, 1.15 service factor electric motor (Baldor CEM4106T). The motor will be controlled via a variable frequency drive. The variable frequency drive (Hitachi SJ200-037LFU) will allow for a variable fan speed from 0 to 3000 RPM. Calculations for the motor selection may be seen in the next section. The motor is supported on the frame by two motor supports. Each motor support is made from two 3 in x 3 in. x 0.25 in steel angles. In between these angles a 2 in. x 2in. x .31 in. angle is welded.
During the material selection phase it was determined that to remain in the scope of our project budget it would be necessary to construct a 1/4 scale demonstration model instead of the full scale rig. The main goal of this operation was to provide a visual model of what our final product would look like. It was not meant to provide meaningful data although a certain amount of data collection can be demonstrated using this model. This model was constructed using aluminum members in place of steel. The engine and fan were simulated using a 6 inch desk fan. This was attached to a dimmer switch in order to provide variable speeds. Sensors from the engineering department were used to simulate data collection in the system. It was machined and assembled at the Penn State Learning Factory.
Team Leader, CAD design.
Engine analysis and design.
Structural design
Sensor Package Design