A Non-Dimensional Consideration in Combustor Axial Stress Computations
Thermal stresses in the combustor of gas-turbines are computed using non-dimensional parameters. Buckingham pi theorem was used to arrange the listed relevant parameters into non-dimensional groups. In testing the validity of the functional relation of the non-dimensional independent parameters, use is made of the prevailing temperatures of the combustor in operation. A computer program was used to enhance computations. The results showed an interesting way of influencing the axial stresses. To reduce stresses in gas-turbine combustors, a method of varying the independent parameter that is of radius ratio oriented and thickness dependent was adopted. This showed a reduction of the axial stresses to minimal levels using the parameters. Plots were made and a point of inflection that manifested itself in the presentation of the axial stress function was further investigated upon. It turned out to be a point of abnormal stress level and out-of-trend temperature profile. The use of non-dimensional consideration proved adequate in the computation of axial stresses. The results showed a 2 percent difference from existing values of stresses got from a transient thermal loading of a combustor.
THREE-DIMENSIONAL TRANSIENT THERMAL STRESS ANALYSIS OF A NONHOMOGENEOUS HOLLOW CIRCULAR CYLINDER DUE TO A MOVING HEAT SOURCE IN THE AXIAL DIRECTION
In this paper, a theoretical analysis of a three-dimensional transient thermal stress problem is developed for a nonhomogeneous hollow circular cylinder due to a moving heat source in the axial direction from the inner and /or outer surfaces. Assuming that the hollow circular cylinder has nonhomogeneous thermal and mechanical material properties in the radial direction, the heat conduction problem and the associated thermoelastic behaviors for such nonhomogeneous medium are developed by introducing the theory of laminated composites as one of theoretical approximation. The transient heat conduction problem is treated with the help of the methods of Fourier cosine transformation and Laplace transformation, and the associated thermoelastic field is analyzed making use of the thermoelastic displacement potential, Michell's function, and the Boussinesq's function. Some numerical results for the temperature change and the stress distributions are shown in figures, and the effect of relaxing the thermal stress ...
The Illinois Legislature
It further provides that the county must have voted "for license" at the last general election on that subject. Also, that the petition, together with all names and addresses on it, must first be published in at least two issues of some newspaper published in the town where the petition was circulated, for at least ten days before the petition is acted upon. Any officer authorized to issue licenses violating the provisions of this act is liable to a fine of from $500 to $1000 and imprisonment in the county jail for from two to twelve months. The act does not repeal any local laws forbidding the sale of liquor, but is cumulative to all anti-liquor laws now in force. The final section is: "This Act being necessary for the public peace, health, and safety, shall take effect and be in force from and after December 31, 1913." The postponement of the time for going into effect was made io order not to interfere with licenses already issued and to give the liquor dealers time to adjust themselves to the provisions of the act. But the liquor people denied that the emergency clause could be attached to an act the operation of which was postponed nearly a year. They called attention to the omission of the word "immediate," and declared that the postponement was in itself sufficient evidence that it was not necessary for the "immmediate preservation of the public health, peace and safety." A petition for reference was circulated and the necessary number of signatures was secured. The attorney-general was first asked for his opinion as to whether the act was subject to the referendum. That officer stated that he could find no precedent for such a case. Basing his decision on reason and common sense he declared the act not subject to the referendum. The circuit court was then asked for a write of mandamus against the secretary of state to compel him to submit the act, but the court refused to grant it, saying that the attachment of the emergency clause was evidence that the legislature intended to prevent its submission. At this writing the question is pending on appeal before the supreme court.