The production of thin-walled investment castings causes severe difficulty during mold filling by liquid metal due to small opening and proportionate large galloping width in annular molds. The filling time calculated by employing mass flow rates using classical Bernoulli’s energy conservation equation obviously deserves certain modifications. The first factor introduced comes from the restriction imposed by small opening in the wide channel in terms of the frictional head loss operating during metal flow. The second one is the kinetic energy factor normalizing the actual velocity of the flowing liquid in the annular channel with its average velocity. The third resistance comes from pressure drop due to the capillary action of the liquid with its vapor phase. The only saving grace though negligible for the ease of filling arises from the suction by the Torricellian vacuum created within the mold. On this basis precision filling time mathematics has been developed for the thin-walled investment casting. Simulation experiments were conducted with liquid mercury, and actual metal castings of aluminum alloy and copper alloys in hot clay molds were produced to verify the developed mathematics. In both occasions, the results were encouraging for justification of the model in regular use.

薄壁熔模铸件的生产由于环形模具中的小开口和成比例的大舞动宽度而在液态金属充模过程中造成严重困难。通过使用经典伯努利能量守恒方程采用质量流量计算的填充时间显然值得进行某些修改。引入的第一个因素来自在金属流动过程中操作时产生的摩擦压头损失，宽通道中的小开口所施加的限制。第二个是动能因数，以其平均速度归一化了环形通道中流动液体的实际速度。第三阻力来自由于液体及其气相的毛细管作用而引起的压降。尽管对于填充的容易性而言可以忽略的唯一节省宽限度是由于模具内产生的Torricellian真空吸引所致。在此基础上，已经为薄壁熔模铸造开发了精确的填充时间数学。用液态汞进行了模拟实验，并制作了在热粘土模具中的铝合金和铜合金的实际金属铸件，以验证所开发的数学模型。在这两种情况下，结果都令人鼓舞，以证明该模型可以正常使用。并在热粘土模具中生产了铝合金和铜合金的实际金属铸件，以验证所开发的数学模型。在这两种情况下，结果都令人鼓舞，以证明该模型可以正常使用。并在热粘土模具中生产了铝合金和铜合金的实际金属铸件，以验证所开发的数学模型。在这两种情况下，结果都令人鼓舞，以证明该模型可以正常使用。